Extrusion bonded laminates for absorbent articles

ABSTRACT

An absorbent article of the present invention may comprise a topsheet, an outer cover, and an absorbent core disposed therebetween. The outer cover may comprise an extrusion bonded laminate. The EBL may comprise a multi-layer coextruded elastomeric film and a nonwoven. The film may comprise a core layer, a first outer layer, and a second outer layer, wherein the core layer is between the first and second outer layers. The nonwoven may comprise fibers and/or filaments. The first outer layer may be non-adhesively joined to the nonwoven via extrusion coating. Further, the outer cover may be elastic to at least about 50% engineering strain. The nonwoven may have high chemical affinity for the first outer layer. The first outer layer may have a low chemical affinity for the core layer; and the multi-layer coextruded elastomeric film may have a basis weight no greater than about 40 gsm.

FIELD OF THE INVENTION

The present invention generally relates to laminates useful forincorporation into absorbent articles. More specifically, the presentinvention relates to the materials and methods for making variouselastomeric extrusion bonded laminates and their incorporation into adiaper.

BACKGROUND OF THE INVENTION

Absorbent articles such as conventional taped diapers, pull-on diapers,training pants, incontinence briefs, and the like, offer the benefit ofreceiving and containing urine and/or other bodily exudates. Suchabsorbent articles can include a chassis that defines a waist openingand a pair of leg openings.

Conventional chassis often include substantially inelastic outer covers.In order to provide for some stretch properties, conventional outercovers can include elastomeric waistbands and elastomeric leg bandssurrounding a portion of the leg openings (e.g., barrier leg cuffs). Theremainder of the outer cover typically includes a non-elastomericnonwoven-film laminate. Undesirably, however, due to thesenon-elastomeric laminates, these articles offer limited conformity to awearer's body in response to body movements (e.g. sitting, standing, andwalking), due to the relative anatomic dimensional changes (which can,in some instances, be up to 50%) in the buttocks and abdominal regioncaused by these movements. This conformity problem is furtherexacerbated because one diaper typically must fit many wearers ofvarious shapes and sizes in a single product size.

The challenge of conformity further resides in the fact that thedimensions of the smallest and biggest wearers within a given productsize range can be markedly different. For instance, in the case ofwearers, the waist circumference at the navel can vary by 80 mm within asize range. Also, the navel-to-back distance, which is the distance fromthe navel, around the crotch, and to a point on the back of the wearerthat is in the same horizontal plane as the navel, can vary by about 80mm from the smallest to the largest wearers in this same size range.

One solution to the above-stated problems is to provide elastomericnonwoven-film laminate (e.g., some combination of a nonwoven with anelastomeric film) that may be used as an outer cover. But providing sucha laminate is no trivial task, especially if one attempts to do soeconomically. First, for the sake of process simplicity and costefficiency, there is a desire to use a minimum of processing or handlingsteps to produce the laminate. Thus, different surfaces or layers of anelastomeric film, having the same chemical and physical properties, mayneed to perform more than one function (e.g., a film layer thatfunctions as a tie layer, as well as a skin layer), or may requirecertain properties during manufacture of an extrusion bonded laminate(EBL), different properties during absorbent article converting, andstill different properties when the absorbent article is used by theconsumer.

Second, there are several desirable embodiments that require thecombination of laminate layers having a low chemical affinity for eachother (e.g., the combination of an inelastic nonwoven and an elastomericfilm). Increasing the penetration of the extrudate into a nonwovenstructure may improve the bonding between these two materials, but thiscan result in a composite structure that is unpleasantly stiff and maybe difficult to activate without damaging the resulting EBL. Thus, a tielayer or an adhesive may need to be employed in order to produce alaminate that can be produced at a reasonable rate, resists separationduring subsequent processing, and maintains a suitable drape or hand. Ifa tie layer is employed (which has advantages over an adhesive,including process simplicity), one needs to not only balance bondstrength between the tie layer and the nonwoven, but also theinteraction between the tie layer and the core layer. For instance, ifthe bond strength to the nonwoven is too high, activation of thelaminate becomes difficult. If, however, the bond strength is too weak,the laminate is subject to delamination. Third, striking the rightbalance in bond strength is further complicated by the need to achieve alaminate having particular extension, recovery, set and tensileproperties.

Fourth, because laminates are often manufactured at a site differentfrom the location where the laminate will be converted into a finishedabsorbent article, there may be a need to build a base laminate thatincludes a skin layer that may enable the base laminate to be wound andunwound after prolonged storage conditions without blocking.

Fifth, it may be desirable to select an activatable nonwoven, a tielayer, or the combination of both that can dissipate energy and avoidunwanted concentration of stresses in the film during mechanicalactivation of the laminate. That is, when using an inelastic nonwoven incombination with an elastic film, the need to activate the laminate willexist. Activation is, however, demanding for the elastic film, and cancause damage to the laminate film (e.g., formation of unwanted holes inthe film), thus creating undesirable laminate properties. Therefore, useof a tie layer may offer the additional advantage of dissipating theenergy of the activation process such that the integrity of the elasticfilm and appearance of the nonwoven is better maintained (i.e., a tielayer that acts as a buffer).

Thus, it is an object of the present invention to provide an elastomericnonwoven-film laminate with good tensile properties. It is a furtherobject of the invention to provide such a laminate comprising one ormore tie layers, the laminate being capable of being mechanicallyactivated without delamination. Another object of the invention is toprovide an elastomeric nonwoven-film laminate as described using no morethan two extruders. Still further, it is an object of the presentinvention to provide an elastomeric nonwoven-film laminate capable ofbeing wound, stored, and unwound within acceptable parameters. Finally,it is an object of the present invention to provide an elastomericnonwoven-film laminate comprising a tie layer that acts as a buffer toenable pinhole-free mechanical activation.

SUMMARY OF THE INVENTION

An absorbent article of the present invention may comprise a topsheet,an outer cover, and an absorbent core disposed therebetween. The outercover may comprise an extrusion bonded laminate. The EBL may comprise amulti-layer coextruded elastomeric film and a nonwoven. The film maycomprise a core layer, a first outer layer, and a second outer layer,wherein the core layer is between the first and second outer layers. Thenonwoven may comprise fibers and/or filaments. The first outer layer maybe non-adhesively joined to the nonwoven via extrusion coating.

Further, the outer cover may be elastic to at least about 50%engineering strain. The nonwoven may have high chemical affinity for thefirst outer layer. The first outer layer may have a low chemicalaffinity for the core layer; and the multi-layer coextruded elastomericfilm may have a basis weight no greater than about 40 gsm.

The extrusion bonded laminate may be activated. The first and secondouter layers may have a fusion index from about 10% to about 20%. Thefirst and second outer layers may be selected from the group consistingof ethylene copolymer, propylene copolymer, and mixtures thereof.

The nonwoven may be activatable and may be selected from the groupconsisting of polypropylene, polyethylene, and combinations thereof.

The nonwoven may comprise bicomponent fibers, the fibers comprising acore and a sheath. The sheath may comprise polyethylene and the corecomprises polypropylene. The polyethylene may have a fusion index fromabout 50% to about 75%. The polypropylene may have a fusion indexgreater than about 50%.

The core of the elastomeric film may be selected from the groupconsisting of ethylene copolymer, propylene copolymer, styrenic blockcopolymers, and mixtures thereof. The core of the elastomeric film maybe selected from the group consisting of an ethylene copolymer having afusion index from about 5% to about 20%, a propylene copolymer having afusion index from about 5% to about 20%, and combinations thereof. Thefirst and second outer layers may each have a fusion index greater thanthe overall fusion index of the core layer.

The EBL may have a basis weight from about 30 to about 70 gsm and mayfurther comprise an adhesive. The nonwoven may comprise fibers that arenot round in cross section. The first outer layer may comprise at leastabout 25% of a polymer comprising more than 10 w % ethylene.

Alternatively, the nonwoven may be an activatable polypropylenemonofilament, and the first outer layer may comprise at least about 25%of a polymer comprising more than 10 w % ethylene.

A second nonwoven may be joined to the second outer layer, wherein thesecond nonwoven is different than the nonwoven joined to the first outerlayer. Each of the nonwovens may be selected from the group consistingof spunbond nonwoven webs, carded nonwoven webs, meltblown nonwovenwebs, and spunlaced nonwoven webs, spunbond meltblown spunbond, spunbondmeltblown meltblown spunbond, unbonded nonwoven, and combinationsthereof.

When the EBL is activated, the laminate bond strength may be from about1.0 to about 1.5 N/cm or from about 2.3 to about 3.5 N/cm, as measuredby the Tensile Test (Mode II).

An exterior surface of the second outer layer may have a blocking forceof less than 0.4 N/cm. The EBL may be adhesive free. The elastomericfilm may have a basis weight from about 20 to about 40 gsm. Theelastomeric film may comprise at least about 50%, by weight, of apolyolefinic elastomer.

Further, the elastomeric film may comprise at least one olefin-basedelastomeric polymer and at least one draw down polymer, wherein theelastomeric film has a permanent set of no more than about 15% asmeasured by the Two-Cycle Hysteresis Test Method using 100% maximumengineering strain. More particularly, the first and second outer layersof the elastomeric film may comprise at least one olefin-basedelastomeric polymer and at least one first draw down polymer; and thecore layer of the elastomeric film may comprise at least one elastomericpolymer and at least one second draw down polymer, wherein theelastomeric film has a permanent set of no more than about 15% asmeasured by the Two-Cycle Hysteresis Test Method using 100% maximumengineering strain.

At least one elastomeric polymer of the core layer may not be anolefin-based elastomeric polymer. The first and second outer layers maybe compositionally identical. The outer cover may have an ultimatetensile strength of greater than about 3 N/cm.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1, 6A, 6B, 6C, 7, and 8 are sectional side views of an EBL usefulin absorbent articles of the present invention.

FIG. 2 is a top plan view of an absorbent article including an EBL ofthe present invention.

FIG. 3 is a sectional side view of the absorbent article of FIG. 2.

FIG. 4 is a graph illustrating tensile properties of activatablenonwovens (three shown) useful in absorbent articles of the presentinvention versus a non-activatable nonwoven (one shown).

FIGS. 5A and 5B are graphs illustrating tensile properties of extrusionbonded laminates useful in absorbent articles of the present invention.From these graphs Mode II failure and peak force at break may bedetermined (see Test Methods).

While the specification concludes with claims particularly pointing outand distinctly claiming the subject matter that is regarded as thepresent invention, it is believed that the invention will be more fullyunderstood from the following description taken in conjunction with theaccompanying drawings. Some of the figures may have been simplified bythe omission of selected elements for the purpose of more clearlyshowing other elements. Such omissions of elements in some figures arenot necessarily indicative of the presence or absence of particularelements in any of the exemplary embodiments, except as may beexplicitly delineated in the corresponding written description. None ofthe drawings are necessarily to scale.

DETAILED DESCRIPTION OF THE INVENTION Definitions

As used herein, the following terms shall have the meaning specifiedthereafter:

“Absorbent article” refers to devices which absorb and contain bodyexudates and, more specifically, refers to devices which are placedagainst or in proximity to the body of the wearer to absorb and containthe various exudates discharged from the body. Exemplary absorbentarticles include diapers, training pants, pull-on pant-type diapers(i.e., a diaper having a preformed waist opening and leg openings suchas illustrated in U.S. Pat. No. 6,120,487), refastenable diapers orpant-type diapers, incontinence briefs and undergarments, diaper holdersand liners, feminine hygiene garments such as panty liners, absorbentinserts, and the like.

“Activatable nonwoven” refers specifically to nonwovens that havemechanical properties that interact well with films during theactivation process. Activatable nonwovens of the present invention givetensile curves (ASTM D882-02, gauge length=5 mm, specimen width=25.4 mm,crosshead speed=2.117 mm/s, deformation direction coinciding with thatapplied during the activation process) characterized by relatively lowmaximum forces and relatively large engineering strains. Specifically,if the nonwoven's curve's maximum force point lies below 4 N/cm at anengineering strain value of greater than 100%, then, for the purposes ofthe present invention, it is deemed to be “activatable.” Examples ofthree activatable nonwovens and one non-activatable nonwoven are shownin FIG. 4. In FIG. 4, each curve's maximum force point is encircled.

“Activated” refers to a material which has been mechanically deformed soas to impart elasticity to at least a portion the material, such as, forexample by incremental stretching. U.S. Pat. Nos. 6,830,800, 5,143,679,and 5,167,897 disclose examples of the activation process.

“Adhesive” refers to compositions comprising one or more thermoplasticpolymers, one or more tackifier resins, and typically a rheologymodifier or plasticizer. Adhesives contain 2% or more of a tackifierresin. An adhesive is generally used to join or bond two or morematerials together by applying it to at least one material and thenbringing it into contact with at least one other material withsufficient force and for a sufficient duration of time, that theadhesive can wet out or spread on each material to join them together(see definition of “tackifier” below).

“Adhesive-free” refers to a laminate where an adhesive is not used tobond the elastomeric member (e.g., elastomeric film) to the nonwoven ornonwovens, and therefore an adhesive is not part of the final laminatestructure.

“Adhesively bonded” or “adhesively laminated” refers to a laminatewherein an adhesive is used to bond an elastomeric member (e.g.,elastomeric film) to a nonwoven(s).

“Bicomponent fiber” refers to fibers or filaments consisting of materialof two different compositions arranged across the cross-section of thefiber or filament. Each composition is typically delivered by a separateextruder to a spin pack designed to arrange the compositions intoarrangements such as sheath-core, side-by-side, segmented pie andislands-in-the-sea. The mutual arrangement of different compositions canbe beneficial in tailoring the chemical affinity between a film and anonwoven in a laminate.

“Blocking” refers to the phenomenon of a film sticking to itself or tothe opposite outer facing side of a composite laminate structure whenthe film or laminate is rolled, folded, or otherwise placed in intimatesurface to surface contact.

“Body-facing,” “inner-facing,” “outer-facing,” and “garment-facing”refer respectively to the relative location of an element or a surfaceof an element or group of elements. “Body-facing” and “inner-facing”imply the element or surface is nearer to the wearer's body during wear(i.e., closer to the wearer's body than a garment-facing surface or anouter-facing surface). “Garment-facing” and “outer-facing” imply theelement or surface is more remote from the wearer during wear (i.e.,element or surface is nearer to the wearer's garments that can be wornover the disposable absorbent article).

“Chemical affinity” refers to the nature of the chemical interactionbetween polymers. Two polymers are said to have a high degree ofchemical affinity if their enthalpy of mixing is close to zero.Conversely, polymers with large enthalpies of mixing (andcorrespondingly large differences in solubility parameter) have littlechemical affinity. (Solubility Parameters, section VII “Single-ValueSolubility Parameters of Polymers”, Polymer Handbook, 3rd Edition, 1989,J. Brandrup, E. H. Immergut, Ed. John Wiley & Sons, New York,Chichester, Brisbane, Toronto, Singapore). The following table shows theapproximate values for the difference in solubility parameter values fora polymer pair to be considered have “low”, “medium” or “high” chemicalaffinity:

Difference in Degree of Solubility Parameter Chemical Affinity(MPa{circumflex over ( )}0.5) low 2.5 or greater intermediate 1.5-2.49high  0-1.49

For example, polyethylene (“PE”) at 16.0 MPâ0.5 and polypropylene (“PP”)at 18.8 MPâ0.5 have a difference of 2.8 MPâ0.5 and therefore exhibit alow degree of chemical affinity. The method use to determine thesolubility parameter of a polymer is described by Robert Hayes in the“Journal of Applied Polymer Science,” volume 5, pages 318-321, 1961.

“Compositionally identical” refers to compositions that have such closeresemblance as to be essentially the same (e.g., two layers of amulti-layer film having nominally the same ingredients in the sameproportions (such as the A layers in an ABA co-extruded film)).

“Crystallization rate” refers to the kinetics of crystal nucleation andgrowth from a polymer melt, as it is cooled in, and following, anextrusion lamination process. Crystallization rate reflects the route bywhich a polymer solidifies from a molten, amorphous state. DifferentialScanning calorimetry (DSC) may be used according to ASTM D 3418 asdescribed in more detail in the Test Methods to determinecrystallization rates of polymers, polymer blends, and formulationscomprising polymers useful in films, including skin and tie layers, ofthe present invention.

“Diaper” refers to an absorbent article generally worn by infants andincontinent persons about the lower torso so as to encircle the waistand legs of the wearer and that is specifically adapted to receive andcontain urinary and fecal waste. As used herein, term “diaper” alsoincludes “pants” which is defined below.

“Disposable” in reference to absorbent articles, means that theabsorbent articles are generally not intended to be laundered orotherwise restored or reused as absorbent articles (i.e., they areintended to be discarded after a single use and may be recycled,composted or otherwise discarded in an environmentally compatiblemanner).

“Disposed” refers to an element being positioned in a particular placewith regard to another element. When one group of fibers is disposed ona second group of fibers, the first and second groups of fibersgenerally form a layered, laminate structure in which at least somefibers from the first and second groups are in contact with each other.In some embodiments, individual fibers from the first and/or secondgroup at the interface between the two groups can be dispersed among thefibers of the adjacent group, thereby forming an at least partiallyintermingled, entangled fibrous region between the two groups. When apolymeric layer (for example a film), is disposed on a surface (forexample a group or layer of fibers), the polymeric layer can belaminated to or printed on the surface.

“Elastic” and “elastomeric” are synonymous and refer to any materialthat upon application of a tensile force, can stretch to an elongatedlength of at least 10% engineering strain, without rupture or breakage.Further, upon release of the applied force, the material may recover atleast 40% of its elongation within one minute at 22° C. For example, amaterial that has an initial length of 100 mm can extend at least to 110mm, and upon removal of the force would retract to a length of 106 mm orless.

“Engineering strain” is the change in length of a specimen (in thedirection of applied stress or strain) divided by the specimen'soriginal length (William D. Callister Jr., “Materials Science andEngineering: An Introduction”, 1985, John Wiley & Sons, Inc. New York,Chichester, Brisbane, Toronto, Singapore). To calculate percentengineering strain, the engineering strain is multiplied by 100.

“Ethylene rich” refers to the composition of a polymeric layer (e.g., asheath of a bicomponent fiber or a skin layer of a film) or a portion ofa layer of an EBL or nonwoven that comprises at least about 80% byweight of polyethylene (including homopolymers and copolymers). Forexample, a sheath of a core-sheath bicomponent fiber, wherein the sheathis comprised of greater than about 80% by weight of a linear, lowdensity polyethylene, is ethylene rich.

“Extensible” refers to any material that upon application of a tensileforce, can stretch to at least 10% engineering strain, without ruptureor breakage. Further, upon release of the applied force, the materialshows less than 40% recovery within one minute at a temperature of 22°C. For example, a material that has an initial length of 100 mm canextend to at least 110 mm, and upon removal of the force would retractto a length of greater than 106 mm.

“Extrusion bonded laminate (‘EBL’)” refers to a multilayer compositeformed by extruding an elastomeric extrudate directly onto at least onenonwoven at or near a nip formed between two calendar rollers, such thatat least some nonwoven fibers penetrate into the soft extrudate film inorder to join the film and the nonwoven. The amount of penetration ofnonwoven into the soft extrudate may be controlled by selecting a nipgap smaller than the caliper of the nonwoven plus the film, by adjustingthe pressure of the rolls, or by other means well understood to one ofordinary skill in the art. In one embodiment, the elastomeric extrudatemay be a monolayer film comprising one or more elastomeric polymers. Inanother embodiment, the elastomeric extrudate may be a coextrudedmultilayer film with one or more outer layers comprising the same ordifferent composition as a core layer of the film.

“Extrusion lamination” or “extrusion coating” refers to processes bywhich a film of molten polymer is extruded onto a solid substrate (e.g.,a nonwoven), in order to coat the substrate with the molten polymer filmto bond the substrate and film together.

“Joined” refers to configurations whereby an element is directly securedto another element by affixing the element directly to the other elementand to configurations whereby an element is indirectly secured toanother element by affixing the element to intermediate member(s) whichin turn are affixed to the other element. Materials may be joined by oneor more bonding processes including adhesive bonding, thermal welding,solvent welding, ultrasonic bonding, extrusion bonding, and combinationsthereof.

“Liquid-permeable” (or “liquid-pervious”) and “liquid-impermeable” (or“liquid-impervious”) refer to the penetrability of materials in thecontext of the intended usage of disposable absorbent articles.Specifically, “liquid permeable” refers to a layer or a layeredstructure having pores, openings, and/or interconnected void spaces thatpermit liquid water to pass through its thickness at less than 5 mbar ofhydrostatic head (as defined by INDA 80.6-01). Conversely, “liquidimpermeable” refers to a layer or a layered structure through thethickness of which liquid water cannot pass through its thickness atless than 5 mbar of hydrostatic head (as defined by INDA 80.6-01). Alayer or a layered structure that is water-impermeable according to thisdefinition may be vapor-permeable, for example permitting transmissionof air and water vapor. Such a vapor-permeable layer or layeredstructure is commonly known in the art as “breathable.”

“Machine direction” (also “MD” or “length direction”) as applied to afilm or nonwoven material, refers to the direction that was parallel tothe direction of travel of the film or nonwoven as it was processed inthe forming apparatus. The “cross machine direction” (also “CD” or“width direction”) refers to the direction perpendicular to the machinedirection.

“Non-adhesively joined” refers to joining two or more materials withoutuse of an adhesive. Non-limiting examples of non-adhesively joinedmaterials include extrusion coating of a web, sonic welding of two ormore webs, pressure bonding of at least one film and one or morenonwovens, etc.

“Outer cover” refers to that portion of the diaper which is disposedadjacent to the garment-facing surface of the absorbent core. Outercovers have tensile properties that enable ease of the application ofthe article, as well as enabling the article to conform to the wearer'sbody. In some embodiments it may prevent the excreta and/or exudatescontained therein from soiling garments or other articles which maycontact the diaper, such as bedsheets and clothing. In theseembodiments, the outer cover may be impervious to liquids. In otherembodiments, the outer cover may be liquid pervious. Outer covers of thepresent invention may comprise an EBL.

“Pant,” “training pant,” “pre-closed diaper,” “pre-fastened diaper,”“pull-on diaper,” and “pant-like garment” as used herein, refer todisposable garments having a waist opening and leg openings designed forinfant, children, or adult wearers. A pant can be configured such thatthe pant has a closed waist and leg openings prior to being donned onthe wearer, or the pant can be configured such that the waist is closedand the leg openings formed while on the wearer. A pant may be preformedby any suitable technique including, but not limited to, joiningtogether portions of the article using refastenable and/ornon-refastenable bonds (e.g., seam, weld, adhesive, cohesive bond,fastener, etc.). A pant may be preformed anywhere along thecircumference of the article (e.g., side fastened, front waist fastened,rear waist fastened). Examples of suitable pants are disclosed in U.S.Pat. No. 5,246,433; U.S. Pat. No. 5,569,234; U.S. Pat. No. 6,120,487;U.S. Pat. No. 6,120,489; U.S. Pat. No. 4,940,464; U.S. Pat. No.5,092,861; U.S. Pat. No. 5,897,545; U.S. Pat. No. 5,957,908; and U.S.Patent Publication No. 2003/0233082 A1.

“Permanent set” is the permanent deformation of a material after removalof an applied load. In the case of elastomeric films, permanent set isthe increase in length of a sample of a film after the film has beenstretched to a given length and then allowed to relax as described inthe Two Cycle Hysteresis Test. Permanent set is typically expressed as apercent increase relative to the original size.

“Propylene rich” refers to the composition of a polymeric layer (e.g., asheath of a bicomponent fiber or a skin layer of a film) or a portion ofa layer of an EBL or nonwoven that comprises at least about 80% byweight of polypropylene (including homopolymers and copolymers). Forexample, a tie layer comprising 96% VISTAMAXX 6102 (16% by weight PE/84%by weight PP), is propylene rich.

“Side panel,” “front ear,” “back ear,” or “ear panel” refers to thatportion of an absorbent article which is disposed adjacent to the outercover or core or topsheet and connect a front waist edge to a back waistedge. Side panels or front/back ears have tensile properties that enableease of the application of the article, as well as enabling the articleto conform to the wearer's body. Side panels or front/back ears of thepresent invention may comprise an EBL. Examples of side panels that maybe used in the present invention are described and illustrated in EP1150833 (referenced as ear panels).

“Skin layer” refers to an outer layer of a coextruded, multilayer filmthat acts as an outer surface of the film during its production andsubsequent processing.

“Tackifier” refers to an adhesive component with a glass transitiontemperature in the range from about 70° C. to about 150° C. thatdecreases the melt viscosity of a rubbery polymer and increases therubbery polymer's glass transition temperature and decreases the rubberypolymer's entanglement density.

“Tie layer” refers to a layer of a coextruded, multilayer film that actsas an intermediary between a core layer of the film and anothermaterial, such that the laminate strength between the core layer and theother material is improved (increased or decreased). The tie layer'scomposition can be adjusted to modify or optimize the chemical andphysical interactions between film and nonwoven. Tie layers of thepresent invention do not contain more than 2% of a tackifier resin, andare substantially continuous over the entire surface of the coextrudedfilm. In the present invention, it may be desirable to have a tie layerand skin layer which are compositionally identical.

“Ultimate tensile strength” is the peak force and refers to the maximumvalue observed in N/cm (i.e., the peak force divided by the samplewidth, for example, at the “break” in FIG. 5A and at the “yield point”in FIG. 5B).

General Description of the Laminates of the Present Invention

Referring to FIG. 1, EBLs of the present invention may include at leastone nonwoven (NW1) (which may have multiple layers, e.g., SMS, SSMMS,etc.) joined to an elastomeric film (which may comprise multiple filmlayers (e.g., A1, B, and A2)). The elastomeric film of the presentinvention may comprise at least one tie layer (A1), and at least onecore layer (B). In certain embodiments, laminates useful in absorbentarticle of the present invention may comprise a skin layer (A2), whichmay be compositionally identical to the tie layer. Further embodimentsof the present invention may comprise two nonwovens (such that (1) afirst nonwoven (NW1) is joined to the EBL via a first tie layer (A1) anda second nonwoven (NW2) is joined to the EBL via a second tie layer (A2)or (2) such that a first nonwoven (NW1) is joined to the EBL via a tielayer (A1) and a second nonwoven (NW2) is joined to the EBL via anadhesive). Still further, as shown in FIGS. 6A, 6B, and 6C, embodimentsof the present invention may include a nonwoven joined to a film via atie layer in combination with one or more adhesives (which may bereferred to as “adhesive assist”). Adhesives 1 and 2 may becompositionally identical or may different. Further, adhesives 1 and 2may be applied by the same or different means (e.g., adhesive 1 may beslot coated while adhesive 2 may be sprayed). FIGS. 7 and 8 illustrateadditional embodiments of the EBLs useful in absorbent articles of thepresent as described above.

Elastomeric Films of the Present Invention

One or more layers of the elastomeric film (illustrated as layers A1, B,and A2 in FIG. 1) may provide the desired amount of extension andrecovery forces during use of the laminate. As mentioned above, theelastomeric film may comprise one or more film layers. Many suitableelastic materials that may be used for one or more layers of theelastomeric film include synthetic or natural rubbers (e.g., crosslinkedpolyisoprene, polybutadiene and their saturated versions (afterhydrogenation), and polyisobutylene), thermoplastic elastomers based onmulti-block copolymers, such as those comprising copolymerized rubberelastomeric blocks with polystyrene blocks (e.g.,styrene-isoprene-styrene, styrene-butadiene-styrene,styrene-ethylene/butylene-styrene, styrene-ethylene/propylene-styrene,and styrene-butadiene/isoprene-styrene, including their hydrogenated andnon-hydrogenated forms), thermoplastic elastomers based onpolyurethanes, polyesters, polyether amides, elastomeric polyolefinsincluding polyethylenes and polypropylenes, elastomeric polyolefinblends, and combinations thereof.

For instance, one useful group of elastomeric polymers that may be usedin the elastomeric film are the block copolymers of vinyl arylene andconjugated diene monomers, such as AB, ABA, ABC, or ABCA blockcopolymers where the A segments may comprise arylenes such aspolystyrene and the B and C segments (for those embodiments comprising Band/or C segments) may comprise dienes such as butadiene or isoprene. Asimilar, newer group of elastomeric polymers are the block copolymers ofvinyl arylene and hydrogenated olefin monomers, such as AB, ABA, ABC, orABCA block copolymers where the A segments may comprise arylenes such aspolystyrene and the B and C segments (for those embodiments comprising Band/or C segments) may comprise saturated olefins such as ethylene,propylene, or butylene. Suitable block copolymer resins are readilyavailable from KRATON® Polymers of Houston, Tex., Dexco™ Polymers LP ofPlanquemine, La., or Septon™ Company of America, Pasadena, Tex.

Another useful group of elastomeric polymers that may be used in theelastomeric film are olefin-based elastomers. In one embodiment, theelastomeric film comprises a polyolefinic elastomer (POE). Examples ofPOEs include olefin block copolymers (OBCs) which are elastomericcopolymers of polyethylene, sold under the trade name INFUSE™ by The DowChemical Company of Midland, Mich. Other examples of POEs includecopolymers of polypropylene and polyethylene, sold under the trade nameVISTAMAXX® by ExxonMobil Chemical Company of Houston, Tex. and/orVERSIFY by Dow Chemical, Midland, Mich.

For the elastomeric film, other polymers may be blended into thecompositions to enhance desired properties. For example, a linearlow-density polyethylene may be added to the film composition to lowerthe viscosity of the polymer melt and enhance the processability of theextruded film. High-density polyethylene may be added to preventage-related degradation of the other polymers. Polypropylene has beenfound to improve the robustness of the elastomer and improve the films'resistance to pinholing and tearing. Additionally, polypropylene-basedthermoplastic elastomer reactor blends (e.g., ADFLEX, available fromLyondellBasell Industries, Laporte, Tex.) may be used to increase thetoughness the film, as disclosed in WO 2007/146149.

Regarding elastomeric polypropylenes, in these materials propylenerepresents the majority component of the polymeric backbone, and as aresult, any residual crystallinity possesses the characteristics ofpolypropylene crystals. Residual crystalline entities embedded in thepropylene-based elastomeric molecular network may function as physicalcrosslinks, providing polymeric chain anchoring capabilities thatimprove the mechanical properties of the elastic network, such as highrecovery, low set and low force relaxation. Suitable examples ofelastomeric polypropylenes include an elastic randompoly(propylene/olefin) copolymer, an isotactic polypropylene containingstereoerrors, an isotactic/atactic polypropylene block copolymer, anisotactic polypropylene/random poly(propylene/olefin) copolymer blockcopolymer, a stereoblock elastomeric polypropylene, a syndiotacticpolypropylene block poly(ethylene-co-propylene) block syndiotacticpolypropylene triblock copolymer, an isotactic polypropylene blockregioirregular polypropylene block isotactic polypropylene triblockcopolymer, a polyethylene random (ethylene/olefin) copolymer blockcopolymer, a reactor blend polypropylene, a very low densitypolypropylene (or, equivalently, ultra low density polypropylene), ametallocene polypropylene, and combinations thereof. Suitablepolypropylene polymers including crystalline isotactic blocks andamorphous atactic blocks are described, for example, in U.S. Pat. Nos.6,559,262, 6,518,378, and 6,169,151. Suitable isotactic polypropylenewith stereoerrors along the polymer chain are described in U.S. Pat. No.6,555,643 and EP 1 256 594 A1. Suitable examples include elastomericrandom copolymers (RCPs) including propylene with a low level comonomer(e.g., ethylene or a higher alpha-olefin) incorporated into thebackbone. Suitable elastomeric RCP materials are available under thenames VISTAMAXX and VERSIFY as mentioned above.

In another embodiment, the inventive elastomeric film may comprisemultiple layers. Further, the elastomeric film may comprise a coextrudedmultilayer film with an ABA-type construction. The two A layers maycomprise the same composition, and form the outer layers of the film,which may also be referred to as the ‘skin,’ ‘surface,’ or ‘tie’ layers.In the present invention, the skin layer may be compositionallyidentical to the tie layer. The B layer, which forms the ‘core’ or‘central’ layer, may be compositionally identical to the A layers, orthe B layer may comprise a composition other than the A layers. Eachlayer of a multilayer elastomeric film may comprise elastomericpolymers, or the layers may comprise either elastomeric or thermoplasticnon-elastomeric polymers, either singly or in combination, in eachlayer.

For the embodiment in which the elastomeric film is a multilayer film ofABA construction, the A layers, which are the skin or tie layers, maycomprise an elastomeric polymer. For the A layers, the use ofpolyolefin-based elastomers may be desired. It has been unexpectedlydiscovered that A layers comprising POEs improve the processability ofthe elastomeric film, as discussed above, even when the core layer is astyrene block copolymer (SBC) or other less-processable polymer. Also asdiscussed above, POEs on the surface of the film may have a greaterchemical affinity for a polyolefinic fabric joined to the surface of thefilm in the laminate. This greater chemical affinity may improve thelaminate strength between the film surface and a nonwoven.

For the B layer or core of the multilayer ABA elastomeric film, the coremay comprise any elastomeric polymer. In one embodiment, the core layermay be an SBC, such as styrene-butadiene-styrene (SBS),styrene-isoprene-styrene (SIS), styrene-ethylenebutadiene-styrene(SEBS), styrene-ethylene-propylene (SEP),styrene-ethylene-propylene-styrene (SEPS), orstyrene-ethylene-ethylene-propylene-styrene (SEEPS) block copolymerelastomers, or blends thereof. SBC elastomers exhibit superiorelastomeric properties. The presence of SBC elastomers in the core layerof the multilayer elastomeric film yields a film that has excellentstretch and recovery characteristics. As discussed previously, however,unsaturated SBC elastomers are prone to thermal degradation when theyare overheated, and saturated SBC's tend to be very expensive.Additionally, SBC's can be difficult to process and extrude into films,especially thin films of the present invention. In another embodiment,the B layer, or core layer of the multilayer film, may be athermoplastic polyolefin, such as the elastomeric polypropylenesmentioned above, the olefin block copolymers of predominantly ethylenemonomers mentioned above, the polypropylene-based thermoplasticelastomer reactor blends mentioned above, and combinations thereof.

In addition to the elastomeric polymer in the core layer, otherpolymeric components may be added to the core layer composition toimprove the properties of the film. For example, a linear low-densitypolyethylene may be added to the film composition to lower the viscosityof the polymer melt and enhance the processability of the extruded film.High-density polyethylene may be added to prevent age-relateddegradation of the other polymers. High-impact polystyrene (HIPS) hasbeen found to control the film modulus, improve the toughness of thefilm, and reduce the overall cost of the elastomeric material.

In the present invention, homopolymer polypropylene (hPP) may be blendedinto the core layer composition to improve processability. hPP is a formof polypropylene which is highly crystalline and containing essentially100% propylene monomer. It has been found that SBC-based elastomericfilms with hPP can be extruded at a thinner gauge and with improvedgauge uniformity, and the addition of hPP may reduce the tendency of thefilm to experience draw resonance during extrusion.

The elastomeric film of the present invention may optionally compriseother components to modify the film properties, aid in the processing ofthe film, or modify the appearance of the film. Viscosity-reducingpolymers and plasticizers may be added as processing aids. Otheradditives such as pigments, dyes, antioxidants, antistatic agents, slipagents, foaming agents, heat and/or light stabilizers, and inorganicand/or organic fillers may be added. These additives may optionally bepresent in one, several, or all layers of a multilayer elastomeric film.

In order to manufacture a thin-gauge elastomeric film, the average basisweight of the elastomeric film may be controlled. If a polymer is hardto process, then the extruded film of that polymer will likely be hardto control. This lack of control is seen in problems like fluctuatingbasis weights, draw resonance, web tear-offs, and other significantproblems. As discussed above, SBC elastomers tend to have relativelypoor processability, and hence it is very hard to manufacture a filmwith a controlled basis weight. These problems are only magnified as oneattempts to manufacture a film with a lower basis weight.

However, by extruding films comprising POE polymers or, alternatively,POE polymer outer layers (e.g., tie or skin layers), the processabilityof the elastomeric film is improved, and the problems associated withbasis weight control are reduced or eliminated. The inventors havediscovered that thin-gauge films are much easier to manufacture, evenwith high concentrations of SBCs in the core layer, when the outerlayers comprise POE polymers.

Another problem with manufacturing lower basis-weight films is theirreduced mass, which causes the extruded polymer web to solidify morerapidly. If the extruded polymer web solidifies too quickly, then thepolymer film is ‘locked’ into the thickness that exists at that time.This situation is directly comparable to the ‘frost line’ experienced inblown film technology. Once the film has solidified, it cannot be easilydrawn to a thinner gauge. This is particularly a problem with elastomerslike unsaturated SBCs, which are prone to thermal degradation whenheated to excessively high temperatures. Simply heating the unsaturatedSBC to a higher temperature to compensate for the reduced mass of theextruded web may not be sufficient.

POE elastomeric polymers, however, are more thermally stable than SBCelastomers, and thus, can be heated to a higher temperature withoutdegradation. This increases the total heat present in the extrudedpolymer web, so the web releases more heat before solidifying. POEs alsosolidify at lower temperatures than do SBCs, so there is a greaterdifferential between the temperature of the extruded polymer and thetemperature at which the film solidifies. The inventors have alsodiscovered, unexpectedly, that coextruding an SBC-based core withinPOE-based outer layers both allows the coextruded multilayer film to beextruded at a higher overall temperature, thereby compensating somewhatfor the reduced-mass heat loss, and also increases the time it takes forthe molten extrudate to solidify. This allows the manufacturer toextrude the multilayer elastomeric polymer film and draw it to a lowerbasis weight before the film solidifies.

It may be desirable for certain aspects of the present invention to usean elastic film that is less than about 65 gsm or less than about 30 gsmor less than 20 gsm, but greater than about 1 gsm, about 5 gsm, or about10 gsm. The approximate basis weights of the films may be measuredaccording to the commonly understood method referred to as “massbalance.” Further, thicknesses of the films may be determined using SEMor optical microscopy.

Elastic films of the present invention may have a thickness or a caliper(which may be referred to as the z-direction thickness) in the rangefrom about 1 μm to about 65 μm (which corresponds from about 0.9 toabout 65 gsm), from about 5 μm to about 30 μm (which corresponds fromabout 4 to about 30 gsm), from about 10 μm to about 20 μm (whichcorresponds from about 9 to about 20 gsm), and from about 12 μm to about17 μm (which corresponds from about 10 to about 17 gsm).

Nonwovens of the Present Invention

The inventive elastomeric film may be combined with a nonwoven. Thenonwovens (illustrated as NW1 and NW2 in FIG. 1) may be activatablesheet-like materials, such as fabrics. The nonwoven of the presentinvention is generally formed from fibers which are interlaid in anirregular fashion using such processes as meltblowing, air laying,coforming, and carding. In some embodiments, the nonwoven may includespunbond fibers in a single layer (S) or multiple layers (SSS). In otherembodiments, fibers of different diameters or compositions may beblended together in a single layer, or fibers of different diameters orcompositions may be present in multiple layers, as inspunbond-meltblown-spunbond (SMS) constructions andspunbond-spunbond-meltblown-meltblown-spunbond (SSMMS) constructions.The fibers of the nonwoven material may be joined together usingconventional techniques, such as thermal point bonding, ultrasonic pointbonding, adhesive pattern bonding, and adhesive spray bonding. Examplesof activatable nonwovens useful in the present invention include thosedescribed in U.S. Pat. No. 6,417,121.

These fabrics may comprise fibers of polyolefins such as polypropyleneor polyethylene, polyesters, polyamides, polyurethanes, elastomers,rayon, cellulose, copolymers thereof, or blends thereof or mixturesthereof. For a detailed description of nonwovens, see “Nonwoven FabricPrimer and Reference Sampler” by E. A. Vaughn, Association of theNonwoven Fabrics Industry, 3d Edition (1992).

One or more components or layers of the nonwoven may comprisebicomponent fibers. The bicomponent fiber may be of any suitableconfiguration. Exemplary configurations include but are not limited tosheath-core, island-in-the-sea, side-by-side, segmented pie andcombinations thereof (as disclosed in U.S. Pat. No. 5,405,682). In oneoptional embodiment of the present invention the bicomponent fibers havea sheath-core configuration. The sheath may be predominately comprisedof polyethylene and the core may be predominately comprised ofpolypropylene. These fibers may have a diameter or equivalent diameterof from about 0.5 micron to about 200 microns or from about 10 and toabout 40 microns.

Typically, the bicomponent fibers described above are consolidated intoa nonwoven web. Consolidation can be achieved by methods that apply heatand/or pressure to the fibrous web, such as thermal spot (i.e., point)bonding. Thermal point bonding can be accomplished by passing thefibrous web through a pressure nip formed by two rolls, one of which isheated and contains a plurality of raised points on its surface, as isdescribed in U.S. Pat. No. 3,855,046. Consolidation methods can alsoinclude, but are not limited to, ultrasonic bonding, through-airbonding, resin bonding, and hydroentanglement. Hydroentanglementtypically involves treatment of the fibrous web with high pressure waterjets to consolidate the web via mechanical fiber entanglement (friction)in the region desired to be consolidated, with the sites being formed inthe area of fiber entanglement. The fibers can be hydroentangled astaught in U.S. Pat. Nos. 4,021,284 and 4,024,612.

All shapes of fibers may be used to form the nonwoven of the presentinvention. Nonwovens comprising “flat” fibers, such as fibers that arerectangular or oblong in cross section, however, may be better joined tothe elastomeric film than nonwoven fabrics with fibers that are circularin cross section. Additionally, notched fibers may be used (i.e.,multilobal, including bilobal and trilobal fibers).

The nonwoven of the present invention may have a basis weight of about 5grams per square meter (gsm) to 75 gsm. In one embodiment, the nonwovenfabric has a basis weight from about 5 to about 30 gsm. Unless otherwisenoted, basis weights disclosed herein are determined using EuropeanDisposables and Nonwovens Association (“EDANA”) method 40.3-90.

The Layers of the Present Invention

Controlling the bond strength between the elastomeric film and thenonwoven of the inventive elastomeric laminate is an important aspect ofthe present invention. Bond strength may be measured using Mode II peelas described under Test Methods. Improved bond strength between thelayers can be achieved by a number of ways, depending on the laminationmethod. If the layers are laminated by an adhesive method, the choice ofadhesive, amount of adhesive, and pattern of adhesive applied to bondthe layers can be adjusted to achieve the desired bond strength.Additionally, for EBLs of the present invention, bond strength betweenfilm and the nonwoven may be controlled by use of a tie layer(illustrated as A1 and A2 in FIG. 1) that may be selected to optimize(including increasing or decreasing the bond strength) the chemicalaffinity between the film and nonwoven. In particular, tie layers thatcontain copolymers of ethylene and propylene, or blends of ethylene- andpropylene-based polymers, can be “tuned” to provide optimal chemicalaffinity with the nonwoven by appropriate choice of the copolymer'sethylene content. For example, in a laminate comprising a bicomponentnonwoven with a polyethylene sheath, a tie layer containing PEhomopolymer may have too great a chemical affinity with the nonwovenwhereas a tie layer containing PP homopolymer generally has too littlechemical affinity. A tie layer comprising an ethylene-propylenecopolymer with intermediate ethylene contents (10-97 wt. %) provides thechemical affinity required for optimal adhesion between film andnonwoven: enough adhesion to avoid delamination but not enough to causeunwanted pinholes in the film during the activation process.

When the layers making up the film are laminated by an extrusionlamination process, the properties of the film must be carefullyselected to manage competing requirements of throughput, bonding, webtension and control, winding, unwinding, and activation, among others.In the case the extruded elastomeric film of the present invention is ofthin gauge (less than about 30 gsm), the extruded film has less mass toretain heat during the extrusion process. Less mass means that theextruded molten laminate tends to solidify very rapidly. As discussedpreviously, this rapid solidification creates problems when trying tomanufacture thinner films. Additionally, if the extruded elastomericfilm solidifies too rapidly, it is harder to achieve adequate bondstrength between the extruded elastomeric film and any nonwovens in anextrusion laminate. This is particularly a problem when the extrudedpolymer of the elastomeric film does not have great chemical affinityfor the materials that comprise the nonwoven substrate. For instance,SBC elastomers do not have strong natural chemical affinity for thepolyolefinic materials typically used for nonwoven substrates. In orderto achieve adequate bond, laminates of SBC elastomers and nonwovensubstrates must rely on mechanical bonding forces, such as thoseachieved by embedding the fibers of the nonwoven into the surface of theelastomeric film. Unfortunately, if the film has solidified beforecontacting the nonwoven, the fibers of the nonwoven cannot be embeddedinto the solidified surface of the film without application ofsignificant pressure. Hence, the bond strength between the layers of thelaminate is poor, and the elastomeric material will tend to delaminateeasily. Furthermore, with the thin gauges of the elastomeric films ofthe present invention, any significant penetration of the fibers intothe film, or deformation of the film from nip or other bonding pressure,may result in unacceptably thin regions of the film that may tear duringsubsequent processing or handling. In still other cases, the chemicalaffinity of the elastomeric film may be sufficiently high that anacceptable laminate bond strength is obtained, but the laminate may bedifficult to activate due to a number of reasons that may include theintimate coupling of the nonwoven substrate and the film during theactivation process. Furthermore, the high chemical affinity of theelastomeric film for the nonwoven may cause issues in storing,transporting and unwinding of the laminate, if the chemical affinityleads to roll blocking.

Regarding this problem, POE elastomers, however, have more chemicalaffinity for the polyolefinic materials in nonwoven, because the POEsare themselves polyolefinic materials. The chemical affinity of POEs fornonwovens means that these laminate layers are more apt to bond, evenwith little mechanical bonding from embedded nonwoven substrate fibers.In addition, because the thin POE-based films do not solidify as rapidlyas the SBC-based materials, the extruded elastomeric film is stillsemi-molten and soft when it contacts the nonwoven, which allows thenonwoven fibers to embed into the film's surface. Hence, the inventorshave observed that POE-based elastomeric films, or alternativelymultilayer elastomeric films comprising POE-based tie layers, formlaminates with stronger bond strength and less tendency to delaminatewith bicomponent nonwovens comprising a PE sheath. The POE-based skinand tie layers of the present invention may be chosen in such a way asto optimize bonding to the nonwoven during the extrusion step ofmanufacture while providing a tack-free surface to allow winding andstorage of bilaminate EBL with little roll blocking.

A further means to improve the bonding of a tie layer to a nonwoven inan EBL of the present invention is by control of the rate ofcrystallization of a polymer or blend of polymers comprising the tielayer. This has many advantages in the thin films of the presentinvention. When taken together with the chemical affinity of the tielayer for a surface of the nonwoven, the rate of crystallization mayfacilitate or limit the penetration of fibers into the surface. Forexample, when a blend of polymers is chosen with a high crystallizationrate, an outer facing surface of the film may be reinforced andstrengthened to resist deformation when contacting a fibrous surface ofa nonwoven in the nip of an extrusion lamination process, withbeneficial effects on the film quality. Of course, too rapid of acrystallization may result in an outer surface that is so resistant toflow that adequate contact with a nonwoven surface is not achieved. Inanother example, therefore, a polymer blend is chosen to reduce the rateof crystallization so that an outer facing surface of the film mayremain soft and able to flow, increasing the contact area and contacttime of a tie layer and nonwoven in an extrusion lamination process. Oneof ordinary skill in the art will recognize that the rate ofcrystallization may be further adjusted by means of nucleation aids,shear conditions, process temperature, plasticizers, and the like, andthat the rate of crystallization may have limited or even no impact onthe fusion index of EBLs useful in absorbent articles of the presentinvention. Crystallization rates of tie layers useful in EBLs of thepresent invention range from about 1 second to about 60 seconds, fromabout 3 seconds to about 30 seconds, or from about 5 seconds to about 20seconds.

Skin Layers of the Present Invention

A challenge of using elastomeric films is that the polymers used to makethe films are inherently sticky or tacky. When elastomeric films areextruded and wound into a roll, the film will tend to stick to itself or“block,” thereby becoming difficult or impossible to unwind. Blockingbecomes more pronounced as the film is aged or stored in a warmenvironment, such as inside a storage warehouse. A similar problemexists when an elastomeric film is extruded onto a nonwoven to make abilaminate and wound onto a roll, since a tacky surface of the film willcome into intimate contact with a substantial portion of an oppositesurface of the bilaminate when wound. This may prevent unwinding of theroll at commercial speeds in the process of making absorbent articlesand may lead to damage to the film, the nonwoven, or to both.

These problems can be addressed in a number of ways. For instance,antiblocking agents may be used. Antiblocking agents, which are usuallyinorganic particulate materials such as silica or talc, and can beincorporated within one or more layers of the film. Antiblocking agentscan also be dusted onto the outer surfaces of extruded film as the filmis being formed. The elastomeric film can also be surface-coated withmaterials that are not sticky, such as a nonblocking polymer, a brittlenonblocking polymer, a surface coating such as a lacquer or ink, andother such powder coatings. Another way to solve this problem is tocoextrude a non-tacky skin layer (illustrated as A2 in FIG. 1—when NW2is not present) as part of the film. The skin layer may be identical(chemically and/or physically) to the tie layer. Thus, referring to FIG.1, if NW2 is present, A2 may act as a second tie layer. If, however, A2forms an exterior surface of the laminate, it may act as a skin layer.In the latter case, a nonwoven may be joined to it in a separate processlater in time via an adhesive or other bonding means (including, thermalbonds, radio frequency bonds, pressure bonds, ultrasonic bonds, welds,stitching, and the like).

The fusion index for the tie and/or the skin layers of the presentinvention may be from about 14% to about 40%. The fusion index for thepolyethylene portion of the nonwoven of the present invention may befrom about 80% to about 100%. And, the fusion index for thepolypropylene portion of the nonwoven of the present invention may begreater than about 50%. Further, the fusion index for the core layer ofthe present invention comprising thermoplastic polyolefin elastomers maybe from about 10% to about 30%.

Skin layers of the present invention may comprise less than 20%, lessthan 15%, or less than 10% of the volume of an inner core layer. It maybe desirable to have a skin layer and tie layer which arecompositionally identical.

Draw Down Polymers of the Present Invention

One or a combination of layers of the EBL may comprise one or acombination of draw down polymers. In embodiments where one or acombination of draw down polymers are present in two or more layers, theamount of draw down polymer (in weight percent) in each layer may beequal or different. Further, the composition of a draw down polymer orblend of draw down polymers present in a first layer may becompositionally identical to or distinct from a draw down polymer orblend of draw down polymers present in a second layer. The draw downpolymer is a polymer that adds or enhances one or more film propertiesor processing properties, such as those that aid in processabilityduring film preparation. For example, the draw down polymer can aid inthe production of reduced-gauge (i.e., thin) films. In some embodiments,the draw down polymer can aid in film extrusion, such as by helping toprovide an increased line speed or reduce draw resonance. Other possibleprocessability benefits from the addition of the draw down polymerinclude improving the melt curtain stability, providing a smooth filmsurface, providing a lower viscosity of the polymer melt, providingbetter resistance to heat (e.g., increasing the film's heat capacity orthermal stability), providing resistance to tearing, providingresistance to pinhole formation, providing a controlled and uniformthickness, or providing a homogeneous composition. The draw down polymercan act as a processing aid that lubricates the die to reduce sticking(e.g., of elastomeric polymers) and flow resistance of the moltenelastomeric resin. Of course, the addition of the draw down polymer canprovide one or a combination of these aids to film extrusion orprocessability.

There are many examples of draw down polymers. For example, a linearlow-density polyethylene (e.g., ELITE™ 5800 provided by Dow ChemicalCorp. of Midland, Mich.) can be added to a layer of the film compositionto lower the viscosity of the polymer melt and enhance theprocessability of the extruded film. High-impact polystyrene (HIPS)(e.g., STYRON™ 485 from Dow Chemical Corp. of Midland, Mich.; IneosNova473D from IneosNova of Channahon, Ill.) can help control the filmmodulus, improve the toughness of the film, and reduce the overall costof the elastomeric material. Polypropylene can improve the robustness ofthe elastomer and improve the films' resistance to pinholing andtearing. Homopolymer polypropylene (hPP) (e.g., INSPIRE™ D118 from DowChemical Corp. of Midland, Mich.; Polypropylene 3622 from TotalPetrochemicals of Houston, Tex.) can be added to improve processability.hPP is a form of polypropylene which is highly crystalline andcontaining essentially 100% propylene monomer. In some embodiments, hPPis added to a layer comprising an elastomeric polymer (e.g., styreneblock copolymers), as discussed below; the addition can result, in someinstances, in a film that can be extruded at a thinner gauge, withimproved gauge uniformity, or with reduced tendency to experience drawresonance during extrusion.

The draw down polymers can be linear low density polyethylene,propylene, homopolymer polypropylene, high impact polystyrene, andmixtures thereof. The draw down polymer can be a polymer which has beenprepared using a single-site catalyst such as a metallocene catalyst andcan be, for example, a polyolefin produced using a metallocene catalyst(e.g., ELITE™ 5800 provided by Dow Chemical Corp. of Midland, Mich.).The identity and amount of draw down polymer can depend on the othercomponents in the layer (e.g., the identity of the olefin-basedelastomeric polymer(s) in the layer), other components of the film or,if applicable, components of the laminate that comprises the film. Thetotal amount of draw down polymer can be present in an amount effectiveto enhance one or more film properties that aid in processability duringfilm preparation; for example, the total amount of draw down polymer canbe present in an amount effective to provide a film gauge of about 25gsm, about 20 gsm, about 15 gsm, or about 10 gsm. The total amount ofdraw down polymer (i.e., the combined amount of the one or more drawdown polymer(s)) can be about 5%, about 10 wt %, about 15 wt %, about 20wt %, about 25 wt %, about 30 wt %, about 35 wt %, about 40 wt %, orabout 45 wt %. The wt % is relative to the layer weight (i.e., totalweight of draw down polymer(s) divided by the total weight of thelayer). In some instances the total amount of the draw down polymer isat least about 5 wt %, at least about 10 wt %, or at least about 15 wt%. The total amount of draw down polymer can be no more than about 20 wt%, no more than about 25 wt %, no more than about 30 wt %, no more thanabout 35 wt %, or no more than about 45 wt %. A fuller description ofdraw down polymers and thin elastomeric films that are useful for makingEBLs and absorbent articles of the present invention can be found in theU.S. patent application titled “Elastomeric Materials,” filed Jan. 23,2009, listing Iyad Muslet as the first named inventor, and usingattorney docket number CLPP-07005.

Adhesives of the Present Invention

Referring to FIG. 1, an adhesive may be used between the NW1 and A1and/or between A2 and NW2. The adhesive may be a hot-melt adhesiveapplied via a slot coater and/or sprayer, for example. According to oneembodiment, the adhesive may be H2031, H2401, or H2861, which arecommercially available from Bostik Inc. of Wauwatosa, Wis. Usingadhesive assist, the adhesive may be applied during the fabrication ofthe EBL by applying it to a surface of the nonwoven (e.g., NW1) justprior to joining the film extrudate, particularly, the tie layer (e.g.,A1). Further, a second nonwoven (e.g., NW2) may be adhesively laminatedwith an outer layer (e.g., A2) of an EBL according to the presentinvention. Still further, the EBL of the present invention (which mayinclude a first and second nonwoven (e.g., NW1 and NW2, respectively)may be adhesively joined to one or more components of an absorbentarticle, including an absorbent core, a waistband, a cuff, a topsheet,etc.

EBLs of the Present Invention

There are several physical properties of the extrusion bonded laminateof the present invention that impact making and storing it, as well ashow the laminate performs as part of an absorbent article. For example,tackiness of the skin layer (A2) affects the ability to unwind thelaminate after storage. Pinholes in the elastomeric layer resulting fromthe activation process may cause the laminate to become water permeableand may cause tearing of the laminate. If the bond strength of thelayers is too strong, activation of the laminate may be compromised; ifthe bond strength is too weak, the layers of the laminate maydelaminate. Further, tensile strength and hysteresis of the laminate mayimpact the integrity and fit of the absorbent article. Tables 5-8illustrate several parameters of examples 1-26 (examples 5, 6, 12, 13,19, 21 are comparative). Beyond the parameters illustrated in Tables5-8, laminates useful in absorbent article of the present invention mayhave parameters as disclosed in the following paragraphs.

Laminates useful in absorbent article of the present invention may havea blocking force of less than about 0.4 N/cm, about 0.24 N/cm, or about0.12 N/cm.

Laminates useful in absorbent article of the present invention may havea basis weight of from about 10 gsm to about 135 gsm, from about 20 gsmto about 100 gsm, from about 40 gsm to about 80 gsm, or from about 50gsm to about 60 gsm.

Laminates useful in absorbent article of the present invention may beelastic to at least about 50%, about 70%, about 100%, and about 130%engineering strain.

Laminates useful in absorbent article of the present invention may havea laminate bond strength from about 0.5 to about 3.5 N/cm or from about1 to about 2 N/cm (see Tensile Test (Mode II)).

Laminates useful in absorbent article of the present invention may havean ultimate tensile strength of greater than about 3 N/cm (see TensileTest (Mode II)).

Laminates useful in absorbent article of the present invention may befree from pinholes.

Laminates useful in absorbent article of the present invention may havea percent engineering strain at break from about 100% to about 500%,from about 120% to about 400%, or from about 150% to about 300%.

Laminates useful in absorbent article of the present invention, as wellas the components that comprise them (e.g., an outer cover, a back orfront ear, a side panel) may be elastic to at least about 50%, about70%, about 100%, or about 130% engineering strain.

Laminates useful in absorbent article of the present invention may havea percent set less than about 10%, force relaxation less than about 40%,and a Cycle 1 unload force at 50% strain of greater than about 0.10 N/cmas measured by the two cycle hysteresis test. In some embodiments, thepercent set of the laminate may be about 20% or less, about 15% or less,or about 10% or less as measured by the two cycle hysteresis test havinga 75% strain first loading cycle and a 75% strain second loading cycle.In other embodiments, the percent set of the laminate may be about 20%or less, about 15% or less, or about 10% or less as measured by the twocycle hysteresis test.

Elastic laminates may be mechanically activated by one or a combinationof activating means, including, activating the web through intermeshinggears or plates, activating the web through incremental stretching,activating the web by ring rolling, activating the web by tenter framestretching, and activating the web in the machine direction between nipsor roll stacks operating at different speeds. Incremental stretchingrollers may be used to activate elastic laminates in the MD, CD, at anangle, or any combination thereof. In some embodiments, the depth ofengagement used for incremental stretching is about 0.05 inches, about0.10 inches, about 0.15 inches, about 0.20 inches, or about 0.25 inches.The depth of engagement can be, for example, at least about 0.05 inchesor at least about 0.10 inches. The depth of engagement can be, forexample, no more than about 0.10 inches, no more than about 0.18 inches,or no more than about 0.25 inches. The pitch of engagement can be, forexample, from about 0.060 inches to about 0.200 inches, from about 0.080inches to about 0.150 inches, or from about 0.100 inches to about 0.125inches. Further, laminates may be activated at commercial rates via, forexample, the ring rolling activation process. The activation may occurimmediately after the extrusion lamination process or may occur as thelaminate is unwound from a roll on which it was stored.

Absorbent Articles of the Present Invention

The laminate of the present invention may make up at least a portion ofone or more components of an absorbent article, including a backsheet,an outer cover, a side panel, a waistband, a front- or back-ear, andcombinations thereof. For instance, the laminate of the presentinvention may make up a portion of the pant or diaper outer coverdisclosed in U.S. Pub. Nos. 2005/0171499, 2008/0208155, 2007/0167929,and 2008-0045917. The laminate may be subjected to additional processingsteps before or after incorporation into an absorbent article. Forexample, one or more components of the absorbent article comprising theEBL may be activated by passing it through intermeshing wheels (ringrolls) to incrementally stretch and deform or break-up the nonwoven,tie, and/or skin layers. Further, one or more components of theabsorbent article comprising the EBL may be apertured to improve airflow through the material and improve the comfort of the absorbentarticle when worn. The EBL may be printed, embossed, textured, orsimilarly modified to improve the aesthetics of the absorbent article oreven to provide some function or feedback to the wearer.

FIGS. 2 and 3 show an absorbent article (illustrated as a pant-likediaper 20) constructed in accordance with the present invention. Thediaper 20 has a longitudinal centerline 100 and a lateral centerline110. The diaper 20 defines an inner surface 50 and an opposing outersurface 52. The inner surface 50 generally includes that portion of thediaper 20 which is positioned adjacent the wearer's body during use(i.e., the wearer-facing side), while the outer surface 52 generallycomprises that portion of the diaper 20 which is positioned away fromthe wearer's body (i.e., the garment-facing side).

The diaper 20, includes a chassis 21 having a first, or front, waistregion 36, a second, or back, waist region 38 opposed to the front waistregion 36, and a crotch region 37 located between the front waist region36 and the back waist region 38. The waist regions 36 and 38 generallyinclude those portions of the diaper 20 which, when the diaper 20 worn,encircle the waist of the wearer. The waist regions 36 and 38 caninclude elastic elements such that they gather about the waist of thewearer to provide improved fit and containment. The crotch region 37 isthat portion of the diaper 20 which, when the diaper 20 is worn, isgenerally positioned between the legs of the wearer.

The outer periphery of the chassis 21 is defined by lateral end edges 56that can be oriented generally parallel to the lateral centerline 110,and by longitudinal side edges 54 that can be oriented generallyparallel to the longitudinal centerline 100 or, for better fit, can becurved or angled, as illustrated, to produce an “hourglass” shapedgarment when viewed in a plan view. In some embodiments, thelongitudinal centerline 100 can bisect the end edges 56 while thelateral centerline 110 can bisect the side edges 54.

The chassis 21 of the diaper 20 generally includes a liquid-permeabletopsheet 22, an outer cover 24, and an absorbent core assembly 23disposed between the topsheet 22 and the outer cover 24.

The core assembly 23 can be positioned on a wearer-facing surface of theouter cover 24. The core assembly 23 can be joined to the outer cover 24via any suitable adhesive or cohesive 32 (as illustrated) or via anyother suitable means known in the art (e.g., thermal bonds, radiofrequency bonds, pressure bonds, ultrasonic bonds, welds, stitching, andthe like). In some embodiments, the core assembly 23 is attached to theouter cover 24 in as few locations as possible; this can make the outercover 24 look and feel softer. Suitable examples for attaching the coreassembly 23 to the outer cover 24 include the attachment means describedin U.S. Pub. No. 2007/0287982. Other suitable examples for attaching thecore assembly to the outer cover include the attachment means describedU.S. Pub. No. 2007/0287983.

On the other hand, in order to make the design more tamper-resistant, itmay be desirable to attach the core assembly 23 to the outer cover 24along at least part, if not all, of the core assembly's 23 periphery; ora small distance (about 5-20 mm) inboard of the periphery. For example,the bond area between the core assembly 23 and the outer cover 24 can beless than about 70%, or, as another example, less than about 50%, or, asyet another example, less than about 20% of the core assembly 23 surfacearea that is attached to the outer cover 24.

The core assembly 23 is the portion of the diaper 20 providing much ofthe absorptive and containment function. The absorbent core assembly 23includes an absorbent core 26, both of which can be disposedsymmetrically or asymmetrically with respect to either or both of thelongitudinal centerline 100 and/or the lateral centerline 110. Asillustrated, the absorbent core 26 and core assembly 23 are symmetricalwith respect to both the longitudinal centerline 100 and the lateralcenterline 110.

The absorbent core 26 can include a wide variety of liquid-absorbentmaterials commonly used in disposable diapers and other absorbentarticles. Examples of suitable absorbent materials include comminutedwood pulp (e.g., air felt creped cellulose wadding); melt blown polymersincluding co-form; chemically stiffened, modified or cross-linkedcellulosic fibers; wraps and tissue laminates; absorbent foams;absorbent sponges; superabsorbent polymers; absorbent gelling materials;or any other known absorbent material or combinations of materials. Theabsorbent core 26 can include (1) a fluid-acquisition component whichacquires fluid exudates and partitions the exudates away from a wearer'sbody, (2) a fluid-distribution component which redistributes fluidexudates to locations displaced from the point of initial exudateloading, and/or (3) a fluid-storage component which retains a majorityof the fluid exudates on a weight basis. A suitable absorbent corecomprising an acquisition layer, a distribution layer, and/or a storagelayer is described in U.S. Pat. No. 6,013,589. A suitable absorbent corehaving minimal absorbent fibrous material (i.e., not more than about 20wt. % based on the weight of the absorbent core) within the absorbentcore is described in U.S. 2004/0167486. Other suitable absorbent coreconfigurations are discussed in U.S. Pub. Nos. 2003/0225382,2006/0155253, and 2006/0155254. It may be desirable to have an absorbentcore and/or absorbent assembly that is free of or substantially free ofany absorbent fibrous material (i.e., air-felt free) as described inU.S. Pub. No. 2005/0171499.

In some embodiments, the core assembly 23 can include a containmentmember 28, such that the absorbent core 26 is disposed between thetopsheet 22 and the containment member 28. In some embodiments, thecontainment member 28 covers a garment-facing surface of the absorbentcore 26, at least in part, and extends laterally beyond the core 26. Thecontainment member 28 can also extend upwardly to cover the lateralsides of the absorbent core 26. The containment member 28 can beconstructed from a woven web, a nonwoven web (with synthetic and/ornatural fibers), an apertured film, and a composite or laminate of anyof the aforementioned materials. In certain embodiments, the containmentmember 28 is an air permeable nonwoven web such as described in U.S.Pat. No. 4,888,231.

The absorbent core assembly can also include a core cover 29 disposed ona wearer-facing surface of the absorbent core 26. The core cover 29 canhelp immobilize the liquid absorbent material of the absorbent core 26.The core cover 29 may generally be a liquid pervious material, such as anonwoven material or tissue.

The components of the core assembly 23 can be joined as described viaany suitable adhesive or cohesive or via any other suitable means knownin the art. Any of the aforementioned layers of the core assembly 23 canbe a single material or can be a laminate or other combination of two ormore materials.

As illustrated, the topsheet 22 is a distinct structural unit thatcovers the absorbent core 23 and may be attached to the outer cover 24,for example via the adhesive or cohesive 32, thereby forming anenclosure for the absorbent core. In an alternate embodiment (notshown), the core assembly 23 can be self-contained by integrating thetopsheet 22 into the core assembly 23, for example by disposing thetopsheet 22 adjacent a body-facing surface of the core cover 29. Thetopsheet 22 can be made from any suitable liquid-permeable material, forexample those described in U.S. Pat. No. 3,860,003, U.S. Pat. No.5,151,092, and U.S. Pat. No. 5,221,274.

As shown, a pair of opposing and longitudinally extending leg cuffs 35are disposed on and extend outwardly from the topsheet 22. The leg cuffs35 provide a seal against the wearer's body and improve containment ofliquids and other body exudates. In the alternate embodiment (not shown)described above in which the core assembly 23 is self-contained andincludes the topsheet 22, the leg cuffs 35 can simply be the extensionof the laterally distal ends of the containment member 28.

The diaper 20 can also include a waistband 43 that generally forms atleast a portion of the end edge 56 and/or a leg elastic (not shown) thatgenerally forms at least a portion of the side edges 54. The waistband43 and leg elastic are those portions of the diaper 20 which areintended to elastically expand and contract to dynamically fit thewearer's waist and legs, respectively, to provide improved fit andcontainment. The elastic waistband 43 can include a segment positionedin the front waist region 36 and/or the back waist region 38, and can bediscretely attached or an integral part of the chassis 21. Examples ofsuitable waistbands include those described in U.S. Pat. No. 4,515,595,U.S. Pat. No. 5,151,092, and U.S. Pat. No. 5,221,274.

The diaper 20 can be preformed by the manufacturer to create a pull-ondiaper or pant, and the diaper can be prefastened by the manufacturer orfastened by the consumer prior to wearing. Specifically, the diaper 20may include left and right closed side seams 34, each disposed atregions proximal to the front and back ends of side edges 54. Each sideseam 34 can be closed by buttressing and subsequently attaching a givenside edge 54 in the front and back waist regions 36 and 38 either usinga permanent seam or refastenable closure member. Suitable permanentseams include, for example, heat seals, adhesive bonds, ultrasonicbonds, high pressure bonds, radio frequency bonds, hot air bonds, heatedpoint bonds, and combinations thereof. Suitable refastenable closuremembers include, for example, hook and loop fasteners, hook and hookfasteners, macrofasteners, tape fasteners, adhesive fasteners, cohesivefasteners, magnetic fasteners, hermaphroditic fasteners, buttons, snaps,and tab and slot fasteners. The side edges 54 can alternatively beattached in an exterior surface-to-exterior surface configuration,interior surface-to-interior surface configuration, or interiorsurface-to-exterior surface (overlapping) configuration.

When in use, the pull-on diaper 20 is worn on the lower torso of awearer, such that the end edges 56 encircle the waist of the wearerwhile, at the same time, the chassis side edges 54 define leg openingsthat receive the legs of the wearer. The crotch region 37 is generallypositioned between the legs of the wearer, such that the absorbent core26 extends from the front waist region 36 through the crotch region 37to the back waist region 38.

In another embodiment (not shown), the principles of the presentinvention as described above with respect to pant-like garments can beequally applied to absorbent articles that are configured as tapeddiapers. In this embodiment, the diapers are not closed prior towearing. Instead, the diapers generally include side panels havingengaging elements. The side panels can be attached to the diaper chassisat either or both of the front and rear waist regions such that theengaging elements, when worn, contact some portion of the diaper on theopposing waist region to seal the diaper. Examples of suitable diapersaccording to the present invention are described in U.S. Pub. No.2008/0114326.

Examples of the Present Invention

Examples of extrusion bonded laminates are described in Tables 1, 2, 3(bi-laminate with one nonwoven) and Table 4 (tri-laminate with twononwovens) which provide the details of the film structure (monolayer ormultilayer), film composition, film basis weight and nonwoven of eachexample. The examples of Table 4 can be read in conjunction with FIG. 1,which illustrates a first nonwoven (NW1), a film comprising a tie layer(A1), a core layer (B), and a skin layer or a second tie layer (A2), aswell as a second nonwoven (NW2). The composition of the film core of allexamples (except examples 5 and 12) is a weight % blend of 92% VISTAMAXX6102 (available from ExxonMobil, Houston Tex.), 1% Ampacet 10562(process aid) and 7% Ampacet 110361 (white masterbatch with 70% TiO₂).Ampacet materials are available from Ampacet Corporation, Cincinnati,Ohio. The composition of the film core of examples 5 and 12 is a weight% blend of 92% Infuse 9107 (available from The Dow Chemical Company ofMidland, Mich.), 1% Ampacet 10562 and 7% Ampacet 110361. Examples 5, 12,6, 13, 19 and 21 are extrusion bonded laminates with a monolayer filmwith no tie layer (A₁) and no skin layer (A₂). Example 7 and 14 areextrusion bonded laminates with a core film and a skin layer (BA₂), anddo not have a tie layer (no A₁); the skin layer (A₂) is a weight % blendof 82% Elite 5800 (draw down polymer) (available from The Dow ChemicalCompany of Midland, Mich.), 9% Fina 3868 (available from TotalPetrochemicals of Houston, Tex.), 1% Luvofilm 9679 (available fromLehmann & Voss & Company, Hamburg, Germany) and 8% PE 20 S (antiblockavailable from Polytechs SAS, Cany Barville, France). Example 25 and 26are extrusion bonded laminates with a core film and a skin layer (BA₂),and do not have a tie layer (no A₁); the skin layer (A₂) is a weight %blend of 50% Elite 5800 (draw down polymer), 32% Equistar M6060(available from Equistar Chemicals, LP, Cincinnati, Ohio, a subsidiaryof LyondellBasell Industries), 9% Fina 3868, 1% Luvofilm 9679 and 8%Polytech PE 20 S.

Examples 1, 2, 3, 4, 8, 9, 10, 11, 20, and 22 of Tables 1, 2 and 3 canbe read in conjunction with FIG. 7, which illustrates a first nonwoven(NW1), a film comprising a tie layer (A1), a core layer (B), and a skinlayer (A2), wherein A1 and A2 are extruded from a first extruder and theB is simultaneously co-extruded from a second extruder such that the A1,A2, and B layers are joined together. And, the NW1 is simultaneouslyunwound and joined to the A1 layer. In these examples, A2 performs as askin layer. These are examples of EBLs with a multilayer film (A1BA2)comprising a tie layer (A1) and a skin layer (A2), where the compositionof A1 is compositionally identical to A2. The tie layers used inexamples 1, 2, 3, 4, 8, 9, 10, 11, 15, 16, 17 and 18 are a weight %blend of Infuse 9107, Ampacet 10562 and Elite 5800 (draw down polymer)and are selected to improve the bonding of the film to the bicomponent(PP/PE, core/sheath) nonwoven in order to reduce the occurrence ofdelamination. The actual weight % amounts for each skin layer formulaare shown in Tables 1 to 4. The tie layer used in examples 20, 22, 23and 24 is a weight % blend of 59% VISTAMAXX 6102, 1% Ampacet 10562 and40% Adflex V109F (available from Basell USA Inc., Elkton, Md. orLaporte, Tex.) and is selected to decrease the bond strength of the filmto the monofilament, PP based Sofspan 200 nonwoven in order to improvethe activation survivability of the extrusion laminate (for example, tominimize or eliminate the formation of unwanted pin holes duringactivation).

The process conditions used to produce the different extrusion laminateexamples are not identical. The process conditions adjusted to provideuniform film include melt temperature, line speed and gap between thetwo combining rolls (controlled by pressure or gap distance) and areshown in Tables 1 to 4. Examples 1 to 14, 19 to 22, 25 and 26 areextrusion bonded laminates with one nonwoven that are subjected toactivation on a high speed research press (HSRP) as described in U.S.Pat. Nos. 7,062,983 and 6,843,134. Activation in the described simulatedring rolling process refers to using aluminum plates with inter-meshingteeth to selectively stretch portions of the laminate such that thenonwoven is broken and/or elongated and the elastic film is able toextend and retract without being unduly encumbered by the nonwoven. Thelaminates useful in the absorbent articles of the present invention maybe activated with the elongation imparted in the cross direction (CD)with a target engineering strain of about 206% (for example with a pairof flat plates with intermeshing teeth having a depth of engagement ofabout 3.56 mm and a pitch of about 2.49 mm) or a target engineeringstrain of about 245% (for example with a pair of flat plates withintermeshing teeth having a depth of engagement of about 4.06 mm and apitch of about 2.49 mm) or a target engineering strain of about 265%(for example with a pair of flat plates with intermeshing teeth having adepth of engagement of about 4.32 mm and a pitch of about 2.49 mm) TheEBL examples are mechanically activated using activation plates havinginter-meshing teeth with a tip radius of 0.1 mm, a root radius of 0.5 mmand tooth height of 10.15 mm. Additional details of activation with theHSRP are shown in Tables 1, 2 and 3 (activation pitch, target maximumactivation strain rate, depth of engagement and average % engineeringstrain of activation). The activated EBLs are allowed to age a minimumof 1 day at 23±2° C. before testing the physical properties. Examples 1to 14 are films extrusion bond laminated to a bicomponent PE/PP (70/30,core/sheath), 18 gsm nonwoven from Fiberweb (Washougal, Wash.). Examples25 and 26 are films extrusion bond laminated to a bicomponent PE/PP(core/sheath), 18 gsm nonwoven from Fiberweb (Peine, Germany). Thefunction of the tie layer (examples 1 to 4 and 8 to 11) is to improvethe laminate bond strength between the bicomponent nonwoven and thefilm. Examples 19 to 22 are films extrusion bond laminated to a 22 gsmmonofilament PP based nonwoven from Fiberweb (Biesheim, France) and thefunction of the tie layer (examples 20 and 22) is to reduce the laminatebond strength to enable better activation survivability. Examples 1 to14, 19 to 22, 25 and 26 are made without the addition of adhesive.

TABLE 1 Examples 1 2 3 4 5 6 7 25 NW1¹ 1 1 1 1 1 1 1 4 A1: weight %(Infuse 9107/Ampacet 10562/ 99/1/0 84/1/15 69/1/30 0/1/99 — — — — Elite5800) B² VM blend VM blend VM blend VM blend Infuse blend VM blend VMblend VM blend A2: weight % (Infuse 9107/Ampacet 10562/ 99/1/0 84/1/1569/1/30 0/1/99 — — — — Elite 5800) A2: weight % (Elite 5800/Fina 3868/ —— — — — — 82/9/1/8 — luvofilm 9679/Polytech PE 20S) A2: weight % (Elite5800/Equistar M6060/ — — — — — — — 50/32/9/1/8 Fina 3868/luvofilm9679/Polytech PE 20S) NW2 — — — — — — — — A1 = A2 yes yes yes yes — — —— total film basis weight 25 gsm 25 gsm 25 gsm 25 gsm 25 gsm 25 gsm 29gsm 22 gsm film basis weight (gsm) A1/B/A2 3/19/3 3/19/3 3/19/3 3/19/30/25/0 0/25/0 0/25/4 0/18/4 Adhesive used? NO NO NO NO NO NO NO NO Melttemperature (° F.) 460 457 455 460 515 450 450 416 Line speed (feet perminute) 235 235 235 238 230 200 247 260 Nip pressure (psi) or Nip Gap(CC) at CC CC CC CC CC 50 psi 80 psi CC combining Rolls³ Details of HighSpeed Research Press (HSRP) activation target maximum activation strainrate (sec⁻¹) 570 570 570 570 570 229 229 229 HSRP activation pitch(inches) 0.098″ 0.098″ 0.098″ 0.098″ 0.098″ 0.098″ 0.098″ 0.098″ Depthof engagement (DOE) inches 0.140″ 0.140″ 0.140″ 0.140″ 0.140″ 0.140″0.140″ 0.140″ Average Strain of activation (%) 206% 206% 206% 206% 206%206% 206% 206% ¹NW1 = 18 gsm (70/30 core/sheath, PP/PE) bicomponentspunbond, produced at Fiberweb (Washougal, Washington). NW1 = 4 = 18 gsmPP/PE core/sheath bicomponent spunbond, #07-HH18-01 from Fiberweb(Peine, Germany) ²VM blend = Vistamaxx 6102 (92%), Ampacet 10562 (1%),Ampacet 110361 (7%) in weight %. Infuse blend = Infuse 9107 (92%),Ampacet 10562 (1%), Ampacet 110361 (7%) in weight % ³Nip gap incontrolled compression (CC) is the gap between the two combining rollsand is approximately the thickness of the materials pressed in theopening (~0.005″).

TABLE 2 Examples 8 9 10 11 12 13 14 26 NW1¹ 1 1 1 1 1 1 1 4 A1: weight %(Infuse 9107/Ampacet 10562/ 99/1/0 84/1/15 69/1/30 0/1/99 — — — — Elite5800) B² VM blend VM blend VM blend VM blend Infuse blend VM blend VMblend VM blend A2: weight % (Infuse 9107/Ampacet 10562/ 99/1/0 84/1/1569/1/30 0/1/99 — — — — Elite 5800) A2: weight % (Elite 5800/Fina 3868/ —— — — — — 82/9/1/8 — luvofilm 9679/Polytech PE 20S) A2: weight % (Elite5800/Equistar M6060/ — — — — — — — 50/32/9/1/8 Fina 3868/luvofilm9679/Polytech PE 20S) NW2 — — — — — — — — A1 = A2 yes yes yes yes — — —— total film basis weight 25 gsm 25 gsm 25 gsm 25 gsm 25 gsm 25 gsm 29gsm 22 gsm film basis weight (gsm) A1/B/A2 3/19/3 3/19/3 3/19/3 3/19/30/25/0 0/25/0 0/25/4 0/18/4 Adhesive used? NO NO NO NO NO NO NO NO Melttemperature (° F.) 460 457 455 460 515 450 450 416 Line speed (feet perminute) 235 235 235 238 230 200 247 260 Nip pressure (psi) or Nip Gap(CC) at CC CC CC CC CC 50 psi 80 psi CC combining Rolls³ Details of HighSpeed Research Press (HSRP) activation target maximum activation strainrate (sec⁻¹) 638 638 638 638 638 256 256 256 HSRP activation pitch(inches) 0.098″ 0.098″ 0.098″ 0.098″ 0.098″ 0.098″ 0.098″ 0.098″ Depthof engagement (DOE) inches 0.160″ 0.160″ 0.160″ 0.160″ 0.160″ 0.160″0.160″ 0.160″ Average Strain of activation (%) 245% 245% 245% 245% 245%245% 245% 245% ¹NW1 = 1 = 18 gsm (70/30 core/sheath, PP/PE) bicomponentspunbond, produced at Fiberweb (Washougal, Washington). NW1 = 4 = 18 gsmPP/PE core/sheath bicomponent spunbond, #07-HH18-01 from Fiberweb(Peine, Germany) ²VM blend = Vistamaxx 6102 (92%), Ampacet 10562 (1%),Ampacet 110361 (7%) in weight %. Infuse blend = Infuse 9107 (92%),Ampacet 10562 (1%), Ampacet 110361 (7%) in weight % ³Nip gap incontrolled compression (CC) is the gap between the two combining rollsand is approximately the thickness of the materials pressed in theopening (~0.005″).

TABLE 3 Examples 19 20 21 22 NW1¹ 3 3 3 3 A1: weight % (Vistamaxx6102/Ampacet 10562/Adflex V109F) — 59/1/40 — 59/1/40 B² VM blend VMblend VM blend VM blend A2: weight % (Vistamaxx 6102/Ampacet10562/Adflex V109F) — 59/1/40 — 59/1/40 NW2 — — — — A1 = A2 — yes — yestotal film basis weight 25 gsm 25 gsm 25 gsm 25 gsm film basis weight(A1/B/A2) 0/25/0 3/19/3 0/25/0 3/19/3 Adhesive used? NO NO NO NO Melttemperature (° F.) 462 462 462 462 Line speed (feet per minute) 230 230230 230 Nip pressure (psi) or Nip Gap (CC) at combining Rolls³ CC CC CCCC Details of High Speed Research Press (HSRP) activation target maximumactivation strain rate (sec⁻¹) 570 570 638 638 HSRP activation pitch(inches) 0.098″ 0.098″ 0.098″ 0.098″ Depth of engagement (DOE) inches0.140″ 0.140″ 0.160″ 0.160″ Average Strain of activation (%) 206 206 245245 ¹NW1 = 3 = 22 gsm monofilament spunbond, Sofspan 200, produced atFiberweb (Biesheim, France). ²VM blend = Vistamaxx 6102 (92%), Ampacet10562 (1%), Ampacet 110361 (7%) in weight %. ³Nip gap in controlledcompression (CC) is the gap between the two combining rolls and isapproximately the thickness of the materials pressed in the opening(~0.005″).

Examples of extrusion bonded laminates with two nonwovens are shown inTable 4, which describes the film structure (monolayer or multilayer),film composition, film basis weight and nonwoven of each example, whichcan be read in conjunction with FIG. 6A. In examples 15, 16, 17, 18, 23and 24, the aged roll of extrusion bilaminate is combined with a secondnonwoven (e.g., NW2) using an adhesive lamination process, with theaddition of approximately 4.5 gsm of Bostik H2031 adhesive to the A2film-NW2 interface, followed by mechanically activation by a ringrolling activation process at a line speed of about 5.3 meter persecond, to form a trilaminate (activation details are shown in Table 4).The EBLs of said examples are allowed to age a minimum of 1 day at 23±2°C. after fabrication before the adhesive lamination process to producethe trilaminate. The activated trilaminate samples are allowed to age aminimum of 1 day at 23±2° C. before testing the physical properties (forexample, the tensile test and the two cycle hysteresis test).

TABLE 4 Examples 15 16 17 18 23 24 NW1¹ 1 1 1 1 3 3 A1: weight % (Infuse9107/Ampacet 10562/Elite 5800) 69/1/30 69/1/30 0/1/99 0/1/99 — — A1:weight % (Vistamaxx 6102/Ampacet 10562/Adflex V109F) — — — — 59/1/4059/1/40 B² VM blend VM blend VM blend VM blend VM blend VM blend A2:weight % (Infuse 9107/Ampacet 10562/Elite 5800) 69/1/30 69/1/30 0/1/990/1/99 — — A2: weight % (Vistamaxx 6102/Ampacet 10562/Adflex V109F) — —— — 59/1/40 59/1/40 NW2⁴ 2 2 2 2 2 2 A1 = A2 yes yes yes yes yes yestotal film basis weight 25 gsm 25 gsm 25 gsm 25 gsm 25 gsm 25 gsm filmbasis weight (gsm) A1/B/A2 3/19/3 3/19/3 3/19/3 3/19/3 3/19/3 3/19/3Melt temperature (° F.) 455 455 460 460 462 462 Line speed (feet perminute) 235 235 238 238 230 230 Nip pressure (psi) or Nip Gap (CC) atcombining Rolls³ CC CC CC CC CC CC Details of On-line High Speedlamination and activation Interface with Adhesive A2-NW2 A2-NW2 A2-NW2A2-NW2 A2-NW2 A2-NW2 Adhesive type (Bostik) H2031 H2031 H2031 H2031H2031 H2031 Adhesive basis weight (gsm) 4.5 gsm 4.5 gsm 4.5 gsm 4.5 gsm4.5 gsm 4.5 gsm Nip Gap 0.005″ 0.005″ 0.005″ 0.005″ 0.005″ 0.005″ linespeed (m/sec) 5.33 5.33 5.33 5.33 5.33 5.33 activation pitch (inches)0.100″ 0.100″ 0.100″ 0.100″ 0.100″ 0.100″ Depth of engagement (DOE)inches 0.160″ 0.170″ 0.160″ 0.170″ 0.160″ 0.170″ Average Strain ofactivation (%) 245 265 245 265 245 265 ¹NW1 = 1 = 18 gsm (70/30core/sheath, PP/PE) bicomponent spunbond, produced at Fiberweb(Washougal, Washington). NW1 = 3 = 22 gsm monofilament spunbond, Sofspan200, produced at Fiberweb (Biesheim, France). ²VM blend = Vistamaxx 6102(92%), Ampacet 10562 (1%), Ampacet 110361 (7%) in weight %. ³Controlledcompression (CC) nip gap is the gap between the two combining rolls andis about the thickness of the materials pressed in the opening(~0.005″). ⁴NW2 = 2 = 20 gsm (70/30 core/sheath, PP/PE) bicomponentspunbond, produced at Fiberweb (Washougal, Washington).

The tensile properties of the extrusion laminate examples 1 to 7 and 25(activated on the HSRP to 0.140″ DOE at 0.098″ pitch) are shown in Table5. The tensile properties of the extrusion laminate examples 8 to 14 and26 (activated on the HSRP to 0.160″ DOE at 0.098″ pitch) are shown inTable 6. Examples 1 to 14, 25 and 26, made with a bicomponent PP/PE(core/sheath) nonwoven, have a basis weight of ˜50 gsm or less, have anultimate tensile strength >3 N/cm and most have stretch at 1 N/cm thatis >70% engineering strain and for some examples >100% engineeringstrain or >120% engineering strain. Examples 7 and 14, with a skin layerand without a tie layer, are examples where the stretch is lower (62%and 82% respectively) and coincides with a higher permanent setfollowing activation. The Mode II failure forces of extrusion laminateswith a tie layer (2.3-3.3 N/cm for examples 1 to 4 and 8 to 11) arehigher than the Mode II failure forces of extrusion laminate without thetie layer (1.0-1.6 N/cm for examples 5 to 7 and 12 to 14, 25 and 26),which demonstrates that the tie layer increases the bond strengthbetween the film and the bicomponent nonwoven.

After activation, the extrusion laminates are inspected visually for pinholes by stretching the material to about 20% engineering strain (forexample, a sample with 100 mm CD length is stretch to about 120 mm CDlength). The nonwoven of examples 13 and 14 do not delaminate easilyfrom the film, however pin holes with a diameter >about 1 mm areobserved in the extrusion laminate. Examples 13 and 14 are produced withpressure at the nip (50 psi and 80 psi, respectively) and the nonwovenfibers penetrated into the film surface which may cause weak spots inthe film and the formation of pin holes in the extrusion laminate duringactivation. Conversely, the nonwoven of examples 25 and 26 (produced incontrol compression mode) delaminates easily from the film and no pinholes with a diameter >about 1 mm are observed. The use of a tie layerin the extrusion laminates enables a good balance between stretch,laminate bond strength and activation survivability (no delamination orunwanted pin holes). Examples 1 to 4 and 9 to 11 (with a tie layer) havegood CD stretch after activation, are well bonded (as mentioned above),do not delaminate and are substantially free of holes having a diameterof greater in size than about 1 mm.

TABLE 5 Examples 1 2 3 4 5 6 7 25 basis weight (gsm) 48 49 48 43 43 4442 37 Tensile Test Results Stretch at 1 N/cm (% engineering strain) 8179 85 97 118 105 62 102 Ultimate tensile strength (N/cm) 3.8 4.0 3.3 3.25.1 4.3 4.2 3.5 Mode II failure force (N/cm) 3.2 3.3 3.0 2.3 1.2 1.1 1.61.0

TABLE 6 Examples 8 9 10 11 12 13 14 26 basis weight (gsm) 50 50 47 44 4345 42 38 Tensile Test Results Stretch at 1 N/cm (% engineering strain)109 102 106 122 144 138 82 129 Ultimate tensile strength (N/cm) 3.5 3.83.1 3.8 5.3 4 3.4 3.4 Mode II failure force (N/cm) 3.3 3.2 3.0 2.5 1.21.1 1.6 1.0

The tensile properties of the extrusion laminate examples 19 and 20(activated on the HSRP to 0.140″ DOE at 0.098″ pitch) and 21 and 22(activated on the HSRP to 0.160″ DOE at 0.098″ pitch) are shown in Table7. Examples 19 to 22 (made with a monofilament Sofspan 200 nonwoven)have a basis weight of ˜55 gsm or less, have an ultimate tensilestrength ranging from 1.2 N/cm to 2.0 N/cm and have stretch at 1 N/cmthat is >100% engineering strain and for some examples >135% engineeringstrain or >160% engineering strain. The Mode II failure forces ofextrusion laminates with a tie layer (1.2-1.3 N/cm for examples 20 and22) are lower than the Mode II failure forces of extrusion laminatewithout the tie layer (1.6-2.0 N/cm for examples 19 and 21), whichdemonstrates that the tie layer decreases the bond strength between thefilm and the monofilament nonwoven.

TABLE 7 Examples 19 20 21 22 basis weight (gsm) 52 49 54 48 Tensile TestResults Stretch at 1 N/cm (% engineering strain) 114 138 139 166Ultimate tensile strength (N/cm) 2.4 1.8 2.7 1.6 Mode II failure force(N/cm) 1.6 1.2 2.0 1.3

The tensile properties of the extrusion laminate examples 15, 17 and 23(activated on-line to 0.160″ DOE at 0.100″ pitch) and 16, 18 and 24(activated on-line to 0.170″ DOE at 0.100″ pitch) are shown in Table 8.The trilaminate examples 15, 16, 17, 18, 23 and 24 have an ultimatetensile strength of >3.2 N/cm and a strain at break of >250% engineeringstrain. The two cycle hysteresis results for examples 15, 16, 17, 18, 23and 24 are also shown in Table 8. The recoverable properties of theextrusion laminates, as measured by the 2 Cycle Hysteresis Test, aredemonstrated by the unload forces at low engineering strain and the lowpercent set. For example, the forces measured in the return cycle of thefirst cycle (C1 unload forces) are >0.15 N/cm at 50% engineering strainand >0.06 N/cm at 30% engineering strain. The low percent set (<10%)after stretching to 130% engineering strain, shows that the extrusionlaminates have desirable elastic properties. Additionally, the forcerelaxation of these extrusion laminates (examples 15, 16, 17, 18, 23 and24), measured at 130% engineering strain, is <40% force relaxation.

TABLE 8 Examples 15 16 17 18 23 24 basis weight (gsm) 67 65 66 67 73 732 Cycle Hysteresis (130% engineering strain) Results (C1 = Cycle 1) C1Load force at 100% strain (N/cm) 1.11 0.95 1.16 0.96 0.89 0.76 C1 Unloadforce at 50% strain (N/cm) 0.16 0.15 0.15 0.15 0.20 0.18 C1 Unload forceat 30% strain (N/cm) 0.08 0.07 0.08 0.07 0.11 0.10 % SET (% strain) 9 109 9 8 8 Force Relaxation (%) 38.5 36.6 38.2 36.2 36.6 33.2 Tensile TestResults Ultimate tensile strength (N/cm) 4.0 3.9 4.5 3.9 3.2 3.2 Strainat break (% engineering strain) 269 265 278 261 313 277

Test Methods

Fusion Index

The fusion index is determined by the measurement specified by ASTMD3418-08 “Standard Test Method for Transition Temperatures andEnthalpies of Fusion and Crystallization of Polymers by DifferentialScanning calorimetry.” To determine a material's fusion index, thematerial's enthalpy of fusion, expressed in Joules/gram as measuredaccording to ASTM D3418, shall be divided by 208 J/g. For example, thefusion index of a polypropylene with an experimentally determinedenthalpy of fusion of 100 J/g is calculated as ((100/208)*100%)=48.1%.Another example: the fusion index of a PE with an experimentallydetermined enthalpy of fusion of 30 J/g is calculated as((30/208)*100%)=14.4%

DSC

Differential Scanning calorimetry (DSC) measurements are performedaccording to ASTM D 3418, where DSC samples are prepared by firstcompression molding a polymer composition into a thin film of around0.003 inches at about 140° C. between teflon sheets. The film isannealed overnight in a vacuum oven, with vacuum drawn, at a temperatureof about 65° C. Samples are punched out of the resulting films using a 6millimeter diameter skin biopsy punch. The samples are massed toapproximately 5-10 milligrams, loaded into small aluminum pans with lids(Perkin Elmer #0219-0041), and crimped using a Perkin Elmer StandardSample Pan Crimper Press (#0219-0048). Thermal tests and subsequentanalyses are performed using a Perkin Elmer DSC 7 equipped with PerkinElmer Thermal Analyses Software version 4.00.

The melting temperature of a film composition is determined by firstheating the DSC sample from about 25° C. to 180° C. at a rate of 20° C.per minute and holding the sample at 180° C. for 3 minutes. The sampleis then quenched to minus 60° C. at a rate of 300° C. per minute, heldfor 3 minutes at minus 60° C., then heated at a rate of 20° C. perminute to 180° C. The melting temperature is taken as the temperature ofthe melting endotherm's peak. If more than one melting endotherm ispresent, the endotherm occurring at the highest temperature is used. Ifno melting peak is present in the second heat but there is one in thefirst heat (which can happen for film compositions that crystallize veryslowly), the sample pan is removed from the DSC, allowed to remain ataround 25° C. for 24 hours, reheated in the DSC from about 25° C. to180° C. at a rate of 20° C. per minute, and then the melting temperatureis taken as the highest peak temperature in this third heat.

The rate of crystallization of a film composition at a crystallizationtemperature of 20 degrees Celcius below its melting temperature isdetermined by first heating the DSC sample to the desired settemperature (which is above the melting temperature of the film),holding the sample at the set temperature for 2 minutes, and thensubjecting the sample to a rapid cooling down to the desiredcrystallization temperature (about 300° C. per minute). As thetemperature is held steady at the crystallization temperature, thecrystallization process is evidenced by the appearance of acrystallization exotherm in the DSC isothermal scan as a function oftime. A single-point characterization of the crystallization rateconsists of reporting the time at which the minimum in the exothermoccurs. The latter is often considered by those skilled in the art as areasonable indication of the half-time crystallization (VA) for thematerial.

One skilled in the art may use this method to determine thecrystallization rate of a film sample taken from, for example, a punchtaken from an absorbent article component (e.g., an outer cover)comprising an EBL (of course one should take care to first remove anyundesired components before making the punch). In this case, additionalcrystallization peaks may be observed due to the presence of additionalcomponents (e.g., nonwoven fibers) but in many cases, these are readilyassigned and do not interfere with the crystallization ratedetermination of the film or film layer of interest.

Blocking Force

All of the steps for this measurement are carried out in a roommaintained at a temperature of 23° C.±2° C. and a relative humidity of50%±5%.

Materials and apparati (all of the following must be located in the sameroom)

For preparing specimens with edges free from defects, notches, nicks,etc.:

-   -   knife equipped with a sharp #11 Xacto-knife blade or similar    -   a steel straight edge is used as a guide for the knife    -   office-grade printer/photocopier paper to sandwich material        during cutting

For Conditioning Samples

-   -   suitable tray or shelf that allows the samples to be kept        reasonably free of contaminants such as dust, aerosols, etc.

For the Application of Pressure

-   -   laboratory oven set at 46 C (Despach LAC or equivalent) with        baffles open.    -   suitable weights and flat, rigid plates to apply a compressive        pressure of 0.686 MPa to the samples.

For the T-Peel Tensile Test

MTS Alliance RT/1 or a machine of similar capability, equipped withgrips that provide a well-defined area of contact along a single narrowband; and the grips hold the sample along an axis perpendicular to thedirection of testing stress, the grips conforming to the descriptiongiven in ASTM D882.

Strips of an absorbent article component comprising an EBL (“material”for this method) 150 mm×25.4 mm (along the material's machine andtransverse directions respectively) are prepared by sandwiching thematerial between sheets of paper and cutting with a straight-edge and asharp #11 Xacto-knife blade or similar. Shorter specimens may be used ifmaterial availability precludes specimens 150 mm in length.

1. Pre-condition the material at a temperature of 23° C.±2° C. and arelative humidity of 50%±5% for at least 24 hours.

2. Stack 5 samples directly on top of each other with edges aligned suchthat body-facing nonwoven side on each sample is facing upwards. Eachsample in the stack should all be consistently aligned in the MD or CD.

3. Subject one or more stacks of five strips to a compressive load of0.686 MPa in the lab oven at a temperature of 46° C.±2° C. for 100hours±1 hour. Leave several millimeters at the end of the stripsuncompressed to facilitate subsequent mounting in the tensile testergrips.

4. Remove pressure from specimens.

5. Remove specimens from oven and allow to equilibrate at a temperatureof 23° C.±2° C. and a relative humidity of 50%±5% for 45 minutes±15minutes.

6. Testing one interface at a time, mount the stack in the tensiletester grips in a T-Peel configuration and run crosshead at a speed of2.12 mm/s (5 inches per minute) for a distance of 100 mm or, in the caseof specimens shorter than 150 mm, until the respective pieces separatecompletely. Use a data acquisition technique that provides a reliableindicator of the maximum force encountered during the peel test.

The maximum force required during the separation of two strips isrecorded as the blocking force, reported as Newtons force per cm widthof film strip. The average of at least four maximum forces is reportedas the material's blocking force. If the strips are so weakly adhered asto separate under their own weight or during mounting, then the blockingforce should be taken as zero.

Tensile Test (Mode II) (for Absorbent Article Component Comprising EBL)

This method is used to determine the force versus engineering straincurve of the extrusion bonded laminate. The tensile properties of thematerials were measured according to ASTM Method D882-02 with thespecifications described below. The measurement is carried out at aconstant cross-head speed of 50.8 cm/min at a temperature of 23° C.±2°C. The relationship between the stretch length and the engineeringtensile engineering strain γ_(tensile) is given by the followingequation:

$\begin{matrix}{{\frac{L}{L_{o}} - 1} = \frac{\gamma_{tensile}}{100}} & \lbrack 1\rbrack\end{matrix}$

where L_(o) is the original length, L is the stretched length andγ_(tensile) is in units of percent. For example, when a sample withinitial gauge length of 5.08 cm is stretched to 10.16 cm, the elongationis 100% engineering strain [((10.16/5.08)−1)*100=100% engineeringstrain] and when a sample with initial gauge length of 5.08 cm isstretched to 35.6 cm, the elongation is 600% engineering strain[((35.6/5.08)−1)*100=600% engineering strain]. The material to be testedis cut into a substantially rectilinear shape. Sample dimensions areselected to achieve the required engineering strain with forcesappropriate for the instrument. Suitable instruments for this testinclude tensile testers commercially available from MTS Systems Corp.,Eden Prairie, Minn. (e.g. Alliance RT/1 or Sintech 1/S) or from InstronEngineering Corp., Canton, Mass. For either the Alliance RT/1 or Sintech1/S instruments listed above, suitable sample dimensions areapproximately 25.4 mm wide by approximately 100 mm long. Shorterspecimens may be used, however, if material availability precludesspecimens 100 mm in length. (within the limitations outlined below).

The following procedure illustrates the measurement when using the abovesample dimensions and either an Alliance RT/1 or Sintech 1/S. Theinstrument is interfaced with a computer. TestWorks 4™ software controlsthe testing parameters, performs data acquisition and calculation, andprovides graphs and data reports.

The grips used for the test are wider than the elastic member. Typically2.00 inch (5.08 cm) wide grips are used. The grips are air actuatedgrips designed to concentrate the entire gripping force along an area ofcontact; and the grips hold the sample along an axis perpendicular tothe direction of testing stress, the grip face set in the upper andlower grips having one flat surface and an opposing face with a 6 mmline contact (half round protrusion) to minimize slippage of the sample.The load cell is selected so that the forces measured will be between10% and 90% of the capacity of the load cell or the force range used.Typically a 100 N load cell is used. The fixtures and grips areinstalled. The instrument is calibrated according to the manufacturer'sinstructions. The distance from the center of the half round of theupper grip face to the center of the half round of the lower grip face(gauge length) is 2.00 inches (50.8 mm), which is measured with a steelruler held beside the grips. The force reading on the instrument iszeroed to account for the mass of the fixture and grips. The instrumentis located in a temperature-controlled room for measurements performedat 23° C.±2° C. The sample is equilibrated a minimum of 1 hour at 23°C.±2° C. before testing. The mass and dimensions of the specimen aremeasured before testing and are used to calculate the basis weight ofthe specimen in grams per square meter (gsm). The specimen is mountedinto the grips in a manner such that the longitudinal axis of the sampleis substantially parallel to the gauge length direction, there is noslack and the force measured is approximately 0.01N. The sample isdeformed at a constant crosshead speed of 20 inches/min. (50.8 cm/min)to about 1000% engineering strain or until the sample breaks or exhibitsa more than nominal loss of mechanical integrity. The force, time anddisplacement are measured during the tensile test at a data acquisitionfrequency of 50 Hz. A minimum of three samples is used to determine theaverage test values. For different sample dimensions, the crossheadspeed is adjusted to maintain the appropriate engineering strain ratefor the test. For example, a crosshead speed of 10 inches/min (25.4cm/min) would be used for a sample gauge length of 1.00 inch (25.4 mm)

For extrusion bonded laminates that exhibit a yield drop, such as shownin FIG. 4, the yield point identifies the % engineering strain afterwhich the force decreases (or does not increase) with increasingelongation, and is usually caused by localized breaking of the nonwovenfibers and/or the onset of delamination of the nonwoven fibers from theelastomeric film. The post yield force region may reach a minimum orplateau. In some examples, the post yield force plateau region isfollowed by the sample breaking (see for example, FIG. 5B). In otherexamples the post yield force plateau region is followed by an increasein force with increasing elongation and ultimately the sample breaks(see for example, FIG. 5A). The post yield plateau force region of theextrusion bonded laminate tensile curve is used to measure the Mode II(sliding or in-plane shear mode) failure force; and the post yieldplateau force region of the extrusion bonded laminate tensile curve isused as an indicator of the extrusion laminate bond strength. The ModeII failure force is reported in N/cm and is the average force in thepost yield minimum or plateau force region, the region being selectedsuch that the percent relative standard deviation of the average (% RSD)is less than 10%. The Mode II failure is described by Richard W.Hertzberg in Deformation and Fracture Mechanics of EngineeringMaterials, 2^(nd) edition, John Wiley & Sons, New York (1976, 1983),page 276.

The tensile test results are reported for each example as one or acombination of the following properties; the percent engineering strainat 1 N/cm force (the elongation at 1 N/cm), the Mode II failure force inN/cm, the percent engineering strain at break, and the ultimate tensilestrength in N/cm (i.e., the peak force divided by the sample width, forexample, at the “break” in FIG. 5A and at the “yield point” in FIG. 5B).A minimum of three samples is used to determine the average test values.

Typical Mode II failure values for well bonded laminates used inabsorbent articles of the present invention are from about 1.1 N/cm toabout 3.5 N/cm for activated samples.

In some cases, it may not be possible to measure the Mode II failureforce of the laminate, for example in cases where the sample breaksbefore the Mode II failure starts. If it is not possible to measure theMode II failure force, the laminate bond strength can be measured by theTensile Test (Mode I) as follows:

Tensile Test (Mode I)

The Mode I T-peel tensile test method is performed at room temperature(23° C.±2° C.). The material to be tested is cut into a substantiallyrectilinear shape. Sample dimensions are to be selected to achieve therequired strain with forces appropriate for the instrument. Suitablesample dimensions are approximately 25.4 mm wide by approximately 100 mmlong. Shorter specimens may be used, however, if material availabilityprecludes specimens 100 mm in length. The length of the sample is thedirection perpendicular to the axis of stretch. Suitable instruments,grips, grip faces, software for data acquisition, calculations, reports,and definition of percent strain are described in the Tensile Test (ModeII) method section above.

The load cell is selected so that the forces measured fall between 10%and 90% of the capacity of the load cell or the force range used.Typically a 25 N load cell is used. The fixtures and grips areinstalled. The instrument is calibrated according to the manufacturer'sinstructions. The distance between the lines of gripping force (gaugelength as described in Tensile Test—Mode II) is 2.54 cm, which ismeasured with a steel ruler held beside the grips. The force reading onthe instrument is zeroed to account for the mass of the fixture andgrips. The samples are equilibrated at 23° C.±2° C. for a minimum of onehour before testing. The mass, length and width of the specimen aremeasured before sample preparation for the T-peel test and are used tocalculate the basis weight of the specimen in grams per square meter(gsm). The samples (approximately 25.4 mm wide by approximately 100 mmlong) are prepared for T-peel test using the following procedure: (1)Mark the sample with a pen, making a line across the 2.54 cm width ofthe sample at a location 2.54 cm from the end of the sample. (2) Stretchthe sample in small increments in the 6.45 cm² area between the pen markand the end of the sample to initiate delamination of the nonwovenfibers from the film. (3) Secure a piece of masking tape (CorporateExpress, MFG# CEB1X60TN, from Paperworks, Inc at pwi-inc.com orequivalent), 5.08 cm long and 2.54 cm wide, centered across the top 2.54cm width of sample on the end of the sample which has been stretched toinitiated delamination, Apply pressure to bond the tape to the sample.In the case of a bi-laminate, the tape is placed on the film surface. Inthe case of a tri-laminate, the tape is placed on the 2.54 cm widesurface opposite to the side for which the laminate bond strength is tobe measured. This tape will support the film portion of the t-peelsample after steps 4 and 5 are complete. (4) Carefully pull the fibersoff of the film on the side of the sample that does not have tape, inthe 6.45 cm² area between the pen mark and the end of the sample. Forsamples that are well bonded, this can be achieved by gently abradingthe sample with a rubber eraser in the approximate direction toward thepen mark. (5) Carefully peel the nonwoven off of the film to the penmark. (6) Place a second piece of tape, 5.08 cm long and 2.54 cm wide,centered across the top 2.54 cm width of the nonwoven fibers that havebeen intentionally delaminated from the sample to form the nonwovenportion of the T-peel sample. A minimum of five samples is used todetermine the average test value. To perform the T-peel test, mount thesample into the grips in a T-peel configuration with the nonwovenportion of the T-peel sample mounted in the upper grip and the filmportion of the T-peel sample mounted into the bottom grip. The specimenis mounted into the grips in a manner such that there is minimal slackand the force measured is less than about 0.02N. The crosshead moves upat a constant crosshead speed of 30.5 cm/min and the sample is peeleduntil the respective materials (nonwoven fibers and film) separatecompletely. The force and extension data are acquired at a rate of 50 Hzduring the peel. The peak force (N/cm) during the first 50 mm ofextension is reported as the Mode I peel force. Typical Mode I peelvalues for a well bonded laminate used in absorbent articles of thepresent invention are from about 1.0 N/cm to about 2.5 N/cm fornon-activated samples and from about 0.5 N/cm to about 2.0 N/cm foractivated samples.

Two Cycle Hysteresis Test

This method is used to determine properties that may correlate with theforces experienced by the consumer during application of the productcontaining the extrusion bonded laminate and how the product fits onceit is applied.

The two cycle hysteresis test method is performed at room temperature(23° C.±2° C.). The material to be tested is cut into a substantiallyrectilinear shape. Sample dimensions are selected to achieve therequired strain with forces appropriate for the instrument. Suitablesample dimensions are approximately 25.4 mm wide by approximately 76.2mm long. Shorter specimens may be used, however, if materialavailability precludes specimens 76.2 mm in length. The sample isselected and mounted such that the direction of elongation in the testmethod is perpendicular to the width of the sample, such that it can beelongated to a length of at least the maximum percent strain of thehysteresis test. Suitable instruments, grips, grip faces, software fordata acquisition, calculations and reports and definition of percentstrain are described in the Tensile Test (Mode II) method section above.

The load cell is selected so that the forces measured fall between 10%and 90% of the capacity of the load cell or the force range used.Typically a 25 N or 100N load cell is used. The fixtures and grips areinstalled. The instrument is calibrated according to the manufacturer'sinstructions. The distance between the line of gripping force (gaugelength, as described in the Tensile test-Mode II) is 2.54 cm, which ismeasured with a steel ruler held beside the grips. The force reading onthe instrument is zeroed to account for the mass of the fixture andgrips. The samples are equilibrated at 23° C.±2° C. for a minimum of onehour before testing. The mass, length and width of the specimen aremeasured before testing and are used to calculate the basis weight ofthe specimen in grams per square meter (gsm). A minimum of five samplesis used to determine the average test values. The specimen is mountedinto the grips in a manner such that there is minimal slack and theforce measured is less than 0.02N. The first segment of the two cyclehysteresis test method is a gauge adjustment step using a 5 gram preloadslack adjustment. The engineering tensile engineering strain γ_(tensile)is defined in the Tensile Test Method section above and with a slackadjustment preload segment, L_(o) is the adjusted gauge length, L is thestretched length and γ_(tensile) is in units of percent. The Two CycleHysteresis Test is done using the following segments:

(1) Slack adjustment: Move the crosshead at 13 mm/min. until thespecified 5 gf slack adjustment preload is achieved. The distancebetween the lines of gripping force at the 5 gf slack adjustment preloadis the adjusted gauge length.

(2) Move the crosshead to achieve the specified percent engineeringstrain (i.e., engineering strain=130%) at a constant crosshead speed of254 mm/min. For example, if the adjusted gauge length from segment 1 is26.00 mm, the sample is stretched to 59.80 mm and the % engineeringstrain=((59.80/26.00)−1)*100=130%.

(3) Hold the sample for 30 seconds at the specified percent engineeringstrain (i.e., engineering strain=130%).

(4) Reduce engineering strain to 0% engineering strain (i.e., returngrips to adjusted gauge length) at a constant crosshead speed of 254mm/min.

(5) Hold the sample for 60 seconds at 0% engineering strain. (segments 1to 5 complete Cycle 1)

(6) Repeat segments 2 through 5 to complete the second cycle of the TwoCycle Hysteresis Test.

The method reports Cycle 1 load forces at 100% engineering strain and130% engineering strain (from segment 2), Cycle 1 unload force at 50%engineering strain and 30% engineering strain (from segment 4), percentset and force relaxation. The forces are reported in N/cm, where cm isthe width of the sample. The percent set is defined as the percentengineering strain after the start of the second load cycle (fromsegment 6) where a force of 7 grams is measured (percent set load=7grams). Force relaxation is the reduction in force during the hold insegment 3 and is reported as a percent. Percent force relaxation iscalculated from the forces measured at 130% engineering strain duringCycle 1 and is equal to 100*[((initial force at 130% engineeringstrain)−(force at 130% engineering strain after the 30 secondhold))/(initial force at 130% engineering strain)].

For different sample dimensions, the crosshead speed is adjusted tomaintain the appropriate strain rate for each portion of the test. Forexample; a crosshead speed of 127 mm/min would be used in segments 2, 4and 6 for a sample gauge length of 12.7 mm and a crosshead speed of 381mm/min would be used in segments 2, 4 and 6 for a sample gauge length of38.1 mm. Additionally, for samples with different widths, the slackpreload force (5 grams per 2.54 cm width=1.97 g/cm) and the percent setload force (7 grams per 2.54 cm width=2.76 g/cm) must be adjusted forthe different sample width. The Two Cycle Hysteresis Test may also bemodified depending on the expected properties of the material tested.For example, if the sample is not capable of being elongated to 130%engineering strain without breaking, the sample is to be elongated to100% engineering strain. And, if the sample is not capable of beingelongated to 100% engineering strain, the sample is to be elongated to70% engineering strain. In the latter two cases (elongation to 100% or70% strain), force relaxation is determined at the maximum elongation ofCycle 1 as defined above for elongation of 130% engineering strain.

Permanent Set

See the Two Cycle Hysteresis Test immediately above.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application, is hereby incorporated herein by reference in itsentirety unless expressly excluded or otherwise limited. The citation ofany document is not an admission that it is prior art with respect toany invention disclosed or claimed herein or that it alone, or in anycombination with any other reference or references, teaches, suggests ordiscloses any such invention. Further, to the extent that any meaning ordefinition of a term in this document conflicts with any meaning ordefinition of the same term in a document incorporated by reference, themeaning or definition assigned to that term in this document shallgovern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. An absorbent article comprising: a topsheet; anouter cover; an absorbent core disposed between the topsheet and outercover; wherein the outer cover comprises an extrusion bonded laminate,the extrusion bonded laminate comprising: a multi-layer coextrudedelastomeric film, comprising a core layer, a first outer layer, and asecond outer layer, wherein the core layer is between the first andsecond outer layers; a nonwoven consisting of fibers and/or filaments;wherein the first outer layer is non-adhesively joined to the nonwovenvia extrusion coating, such that the first outer layer is a tie layerbetween the core layer and the nonwoven; wherein the second outer layeris non-adhesively joined to the core layer, such that the second outerlayer is a skin layer; wherein the first and second outer layerscomprise polyolefin elastomers (POEs); wherein the first and secondouter layers comprise a blend of two ethylene rich copolymers, whereinethylene is between 10% and 97%; wherein the extrusion bonded laminateis mechanically activated using intermeshing gears; wherein the outercover is elastic at 50% engineering strain; wherein the nonwoven has ahigh chemical affinity for the first outer layer; wherein the firstouter layer has a low chemical affinity for the core layer; wherein thelaminate bond strength is from 1 N/cm to 3.5 N/cm; and wherein the corelayer comprises at least one thermoplastic elastomeric polymer.
 2. Theabsorbent article of claim 1, wherein the thermoplastic elastomericpolymer is selected from the group consisting of thermoplasticelastomers based on multi-block copolymers, thermoplastic elastomersbased on polyurethanes, polyesters, polyether amides, elastomericpolyolefins, polyethylenes, polypropylenes, elastomeric polyolefinblends, and combinations thereof.
 3. The absorbent article of claim 2,wherein the thermoplastic elastomers based on multi-block copolymers arecopolymerized rubber elastomeric blocks with polystyrene blocks,selected from the group consisting of styrene-isoprene-styrene,styrene-butadiene-styrene, styrene-ethylene/butylene-styrene,styrene-ethylene/propylene-styrene,styrene-ethylene-ethylene/propylene-styrene, andstyrene-butadiene/isoprene-styrene, including their hydrogenated andnon-hydrogenated forms, and combinations thereof.
 4. The absorbentarticle of claim 1, wherein the outer cover is substantially free ofholes having a diameter of greater in size than about 1 mm.
 5. Theabsorbent article of claim 1, wherein the first and second outer layershave a fusion index from 10% to 20%.
 6. The absorbent article of claim1, wherein the nonwoven comprises bicomponent fibers, the fiberscomprising a core and a sheath.
 7. The absorbent article of claim 6,wherein the sheath comprises polyethylene and the core comprisespolypropylene.
 8. The absorbent article of claim 1, wherein the core ofthe elastomeric film is selected from the group consisting of anethylene copolymer having a fusion index from about 5% to about 20%, apropylene copolymer having a fusion index from about 5% to about 20%,and combinations thereof.
 9. The absorbent article of claim 1, whereinthe extrusion bonded laminate has a basis weight from about 30 gsm toabout 70 gsm.
 10. The absorbent article of claim 1, wherein theextrusion bonded laminate further comprises an adhesive.
 11. Theabsorbent article of claim 1, further comprising a second nonwovenjoined to the second outer layer.
 12. The absorbent article of claim 1,wherein the extrusion bonded laminate is adhesive free.
 13. Theabsorbent article of claim 1, wherein the elastomeric film comprises atleast about 20% to about 80%, by weight, of a styrenic block copolymerelastomer resin.
 14. The absorbent article of claim 1, wherein the firstand second outer layers are compositionally identical.
 15. The absorbentarticle of claim 1, wherein the elastomeric film comprises: at least oneolefin-based elastomeric polymer; at least one styrene block copolymerelastomer resin; and at least one draw down polymer; and wherein theelastomeric film has a permanent set from 8 to 15% as measured by theTwo-Cycle Hysteresis Test Method using 100% maximum engineering strain.16. The absorbent article of claim 1, wherein the level of stretch ofthe activated laminate (% engineering strain at 1 N/cm force, asmeasured by the tensile test) is about 50% to about 144%.
 17. Theabsorbent article of claim 1, wherein the multi-layer coextrudedelastomeric film has a basis weight from 10 gsm to 40 gsm.
 18. Anabsorbent article comprising an extrusion bonded laminate, wherein theextrusion bonded laminate is at least a portion of one or morecomponents of the article, said components selected from the groupconsisting of a backsheet, an outer cover, a side panel, a waistband, afront ear, a back ear, and combinations thereof; wherein the extrusionbonded laminate comprises: a multi-layer coextruded elastomeric film,comprising a core layer, a first outer layer, and a second outer layer,wherein the core layer is between the first and second outer layers; anonwoven consisting of fibers and/or filaments; wherein the first outerlayer is non-adhesively joined to the nonwoven via extrusion coating,such that the first outer layer is a tie layer between the core layerand the nonwoven; wherein the second outer layer is non-adhesivelyjoined to the core layer, such that the second outer layer is a skinlayer; wherein the first and second outer layers comprise polyolefinelastomers (POEs); wherein the first and second outer layers comprise ablend of two ethylene rich copolymers, wherein ethylene is between 10%and 97%; wherein the extrusion bonded laminate is mechanically activatedusing intermeshing gears; wherein the component comprising the extrusionbonded laminate is elastic at 50% engineering strain; wherein thenonwoven has a high chemical affinity for the first outer layer; whereinthe first outer layer has a low chemical affinity for the core layer;wherein the laminate bond strength is from 1 N/cm to 3.5 N/cm; andwherein the core layer comprises at least one thermoplastic elastomericpolymer.
 19. The absorbent article of claim 18, wherein at least one ofthe components of the article comprising the extrusion bonded laminatehas apertures.
 20. The absorbent article of claim 18, wherein thethermoplastic elastomeric polymer is selected from the group consistingof thermoplastic elastomers based on multi-block copolymers,thermoplastic elastomers based on polyurethanes, polyesters, polyetheramides, elastomeric polyolefins, polyethylenes, polypropylenes,elastomeric polyolefin blends, and combinations thereof; and wherein thethermoplastic elastomers based on multi-block copolymers arecopolymerized rubber elastomeric blocks with polystyrene blocks,selected from the group consisting of styrene-isoprene-styrene,styrene-butadiene-styrene, styrene-ethylene/butylene-styrene,styrene-ethylene/propylene-styrene,styrene-ethylene-ethylene/propylene-styrene, andstyrene-butadiene/isoprene-styrene, including their hydrogenated andnon-hydrogenated forms, and combinations thereof.